Journal articles on the topic 'Topographic evolution of mountains'
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1
Bao, G., Y. Dou, T. A. Ehlers, P. Li, Y. Wang, and Z. Xu. "Quantifying Tectonic and Geomorphic Interpretations of Thermochronometer Data with Inverse Problem Theory." Communications in Computational Physics 9, no. 1 (January 2011): 129–46. http://dx.doi.org/10.4208/cicp.090110.270410a.
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AbstractThermochronometer data offer a powerful tool for quantifying a wide range of geologic processes, such as the deformation and erosion of mountain ranges, topographic evolution, and hydrocarbon maturation. With increasing interest to quantify a wider range of complicated geologic processes, more sophisticated techniques are needed. This paper is concerned with an inverse problem method for interpreting the thermochronometer data quantitatively. Two novel models are proposed to simulate the crustal thermal fields and paleo mountain topography as a function of tectonic and surface processes. One is a heat transport model that describes the change of temperature of rocks; while the other is surface process model which explains the change of mountain topography. New computational algorithms are presented for solving the inverse problem of the coupled system of these two models. The model successfully provides a new tool for reconstructing the kinematic and the topographic history of mountains.
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Tranel, Lisa, and James Spotila. "Relief History and Coupling of Erosional Processes in the Teton Range, Wyoming." UW National Parks Service Research Station Annual Reports 30 (January 1, 2006): 158–63. http://dx.doi.org/10.13001/uwnpsrc.2006.3683.
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Erosional processes influence topographic relief in mountain landscapes, but the spatial variation between differential processes and influence on tectonic uplift is poorly understood. Deep canyons and adjacent high peaks distinguish the Teton Mountains from nearby ranges, making it an ideal location to study how glacial, fluvial, and hillslope erosion interact to maintain high topographic relief. The purpose of this study is to quantify erosion rates of individual geomorphic processes in this complex system using a variety of techniques to see how each process contributes to landscape evolution in this mountain range.
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Wu, Li, Binggeng Xie, Xiao Xiao, Bing Xue, and Jingzhong Li. "Classification Method and Determination of Mountainous Area Types at Township Scales: A Case Study of Yuxi City, Yunnan Province." Complexity 2020 (September 3, 2020): 1–13. http://dx.doi.org/10.1155/2020/3484568.
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The high-resolution regional division of mountainous area types has important scientific significance for promoting precise management of land space and regional sustainable development. At present, the classification method of mountainous area types is mainly at the county level and above, while classifications for towns and villages are nearly nonexistent, which poses a technical challenge for rural revitalization and the construction of ecological civilization in mountainous areas. We used Yuxi city, Yunnan Province, as the target area of this research, which was based on GIS technology and Digital Elevation Model (DEM) data and socioeconomic environmental monitoring data. The most appropriate statistical unit (e.g., 2.8224 km2) for topographic relief was defined, and the study area was divided into six mountain types: flatlands, hills, low mountains, medium-low mountains, midmountains, and subhigh mountains. Based on the township scale, an index system and classification method dominated by the plain comprehensive index were established to carry out mountain area classifications at township scales. The 75 towns of Yuxi city can be classified into 27 plain towns, 23 mountain-plain towns, and 25 mountain towns from an empirical application perspective, which can provide strong data support and a reference basis for studying the evolution characteristics of land use in different geographical spaces and their interrelationships as well as differentiated land space planning and governance.
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Williams, Timothy C., Janet M. Williams, Peter G. Williams, and Paul Stokstad. "Bird Migration Through a Mountain Pass Studied With High Resolution Radar, Ceilometers, and Census." Auk 118, no. 2 (April 1, 2001): 389–403. http://dx.doi.org/10.1093/auk/118.2.389.
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Abstract Autumnal migration was studied with high-resolution radar, ceilometer, and daily census in the area of Franconia Notch, a major pass in the northern Appalachian Mountains. Under synoptic conditions favorable for migration, broadfront movements of migrants toward the south passed over the mountains, often above a temperature inversion. Birds at lower elevations appeared to be influenced by local topography. Birds moving southwest were concentrated along the face of the mountain range. Birds appeared to deviate their flights to follow local topography through the pass. Specific migratory behavior was not associated with species or species groups. Under synoptic conditions unfavorable for southward migration, multimodal movements probably associated with local flights were as dense as the southward migrations described above. Avian migrants reacting to local terrain may result in concentrations of migrants over ridge summits or other topographic features.
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Bi, Rui, Shu Gan, Xiping Yuan, Raobo Li, Sha Gao, Min Yang, Weidong Luo, and Lin Hu. "Multi-View Analysis of High-Resolution Geomorphic Features in Complex Mountains Based on UAV–LiDAR and SfM–MVS: A Case Study of the Northern Pit Rim Structure of the Mountains of Lufeng, China." Applied Sciences 13, no. 2 (January 4, 2023): 738. http://dx.doi.org/10.3390/app13020738.
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Unmanned aerial vehicles (UAVs) and light detection and ranging (LiDAR) can be used to analyze the geomorphic features in complex plateau mountains. Accordingly, a UAV–LiDAR system was adopted in this study to acquire images and lidar point-cloud dataset in the annular structure of Lufeng, Yunnan. A three-dimensional (3D) model was constructed based on structure from motion and multi-view stereo (SfM–MVS) in combination with a high-resolution digital elevation model (DEM). Geomorphic identification, measurement, and analysis were conducted using integrated visual interpretation, DEM visualization, and geographic information system (GIS) topographic feature extraction. The results indicated that the 3D geomorphological visualization and mapping were based on DEM, which was employed to identify the dividing lines and ridges that were delineated of the pit rim structure. The high-resolution DEM retained more geomorphic detail information, and the topography and the variation between ridges were analyzed in depth. The catchment and ponding areas were analyzed using accurate morphological parameters through a multi-angle 3D visualization. The slope, aspect, and topographic wetness index (TWI) parameters were analyzed through mathematical statistics to qualitatively and accurately analyze the differences between different ridges. This study highlighted the significance of the UAV–LiDAR high-resolution topographic measurements and the SfM–MVS 3D scene modelling in accurately identifying geomorphological features and conducting refined analysis. An effective framework was established to acquire high-precision topographic datasets and to analyze geomorphological features in complex mountain areas, which was beneficial in deepening the research on numerical simulation analysis of geomorphological features and reveal the process evolution mechanism.
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Gong, Ming-Hao, and Yan-Ling Song. "Topographic habitat features preferred by the Endangered giant panda Ailuropoda melanoleuca: implications for reserve design and management." Oryx 45, no. 2 (April 2011): 252–57. http://dx.doi.org/10.1017/s0030605310001043.
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AbstractThe effect of landscape on populations is of great importance, especially given the number of species inhabiting patchy landscapes. Developments in geographical information systems are facilitating a greater application of spatial analyses to threatened species, such as the Endangered giant panda Ailuropoda melanoleuca, for which habitat patchiness and quality are key limiting factors. Of all factors that influence the suitability of habitat for the giant panda, topography is not subject to change. Here, we report a spatial and statistical analysis of the high quality topographic habitat preferred by the giant panda across its stronghold in the Qinling Mountains, China. High quality topographic habitat, as indicated by a combination of elevation, slope and aspect, covers 92,788 ha, accounting for 15% of the current range of the species. The distribution of the giant panda closely follows patterns of topography and areas with patches of high quality topographic habitat are strongly associated with areas supporting greater numbers of giant pandas. However, comparisons between our model and the existing reserve system reveals a number of inadequacies. Some of the reserves contain little high quality topographic habitat and many patches of high quality topographic habitat are unprotected. Given the importance of topography and the decisive role it plays in shaping habitat, landscapes containing high quality topographic features must be a critical consideration in the design of reserves for the giant panda. The existing system of nature reserves is heavily weighted towards judicial and administrative boundaries, to the detriment of other factors such as topography.
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Poole, Kim G., Kari Stuart-Smith, and Irene E. Teske. "Wintering strategies by mountain goats in interior mountains." Canadian Journal of Zoology 87, no. 3 (March 2009): 273–83. http://dx.doi.org/10.1139/z09-009.
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As with many ungulates inhabiting areas with potentially deep snow, winter is an important season for mountain goats ( Oreamnos americanus (de Blainville, 1816)) and is characterized by restricted movements and high juvenile mortality. We examined winter habitat selection and wintering strategies by mountain goats in two adjacent areas of southeastern British Columbia characterized by deep, moist snow and by shallow, dry snow. Fifteen GPS collars were placed on mountain goats in each area over two winters. Winter-range size did not differ between areas and comprised, on average, 2.2%–7.4% of male home range and 8.0%–14.1% of female home range. Topographic variables dominated habitat model selection. At the broad scale, mountain goats in both areas selected winter ranges closer to escape terrain on warmer aspects that contained lesser amounts of mature dense forest. At the fine scale, mountain goats in both areas selected rugged habitat at upper mid-elevations and on warmer aspects. Alpine areas were avoided in the deep snow area and selected in the shallow snow area. No selection for mature forests was observed in either area. Mountain goats, therefore, appeared to utilize open, high-elevation habitats in shallow snow zones, but they did not seek reduced snow levels in mature forest stands in deep snow areas.
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Farah, Tahar, Nasr-Eddine Taibi, and Mohamed Chouieb. "Evolution of Land Cover in the Traras MTS. Region Between 1984 and 2020 by Remote Sensing and Gis (Northwest Algeria)." Ekológia (Bratislava) 41, no. 4 (December 1, 2022): 375–85. http://dx.doi.org/10.2478/eko-2022-0038.
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Abstract In Algeria, the mountainous zones represent 11% of agricultural land of the country and are home to 25% of the population. The economic development and the associated urbanization have led to environmental degradation in the Traras Mountains, which are part of the Atlas Mountains. With the aim to evaluate the degradation consequences of this region, we focused on the evolution of land use and land cover over 36 years (1984–2020). Accordingly, we used Landsat and Google Earth Pro images, topographic and ecological inventory maps, as well terrain truth; our analysis tools were mainly based on ArcGIS, Global Mapper, and ENVI software. The diachronic analysis showed that the Traras Mountains lost 8,100 ha of agricultural and forestland between 1984 and 2020. Relating to this, we point out the destruction of 9,200 ha of forested area by the fire. The urbanization also contributed to the loss of agricultural and forested areas (6,300 ha), of which 27% are located in the coastal zone. The built-up situation led to an increase of soil impermeability which causes flooding during heavy rainfall.
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Bíl, Michal. "Using GIS to detect neotectonics in the Vsetínské vrchy Mountains and in their surroundings." Geografie 108, no. 2 (2003): 101–14. http://dx.doi.org/10.37040/geografie2003108020101.
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This paper discusses the advantages of GIS and numerical analysis in neotectonic studies. An accurate DEM is important for numerous geomorphic and hydrologic applications, particularly over large areas. The method is illustrated on the DEM of the Vsetínské vrchy Mountains, a 367 square km large area in the east of the Czech Republic. Comparing geological maps with large-scale morphometry shows a relationship between the rock resistance and topography. On average, higher mean elevations and steep slopes correlate well with regions of hard bedrock geology. The results together with new geological and geophysical findings show that the evolution of this part of the Outer Western Carpathian topography was proceeding continually. There is no reason to assume the presence of any periods of tectonic standstill here. The topographic relief probably has experienced the state of dynamic equilibrium.
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Ollier, C. D., and C. F. Pain. "Neotectonic mountain uplift and geomorphology." Geomorphology RAS, no. 4 (November 8, 2019): 3–26. http://dx.doi.org/10.31857/s0435-4281201943-26.
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Mountains are topographic features caused by erosion after vertical uplift or mountain building. Mountain building is often confused with orogeny, which today means the formation of structures in fold belts. The common assumption that folding and mountain building go together is generally untrue. Many mountains occur in unfolded rocks, granites and volcanic rocks, so there is no direct association of folding and mountain building. In those places where mountains are underlain by folded rocks the folding pre-dates planation and uplift. The age of mountains is therefore not the age of the last folding (if any) but the age of vertical uplift. Since mountains are not restricted to folded rocks, lateral compression is not required to explain the uplift.
A compilation of times of uplift of mountains around the world shows that a major phase of tectonic uplift started about 6 Ma, and much uplift occurred in the last 2 Ma. This period is known as the Neotectonic Period. It is a global phenomenon including mountains on passive continental margins, and those in deep continental interiors. Several hypotheses of mountain building have problems with this timing. Some fail by being only able to make mountains out of folded rock at continental margins. Many translate the vertical uplift into lateral compression, but vertical uplift alone can create mountains.
The Neotectonic Period has important implications for geomorphology, climate and global tectonics. In geomorphology it does not fit into conventional theories of geomorphology such as Davisian or King cycles of erosion. Neotectonic uplift might initiate several cycles of erosion, but most planation surfaces are much older than the Neotectonic Period. The increasing relief associated with Neotectonic uplift affected rates of erosion and sedimentation, and also late Cenozoic climate.
The Neotectonic Period does not fit within plate tectonics theory, in which mountains are explained as a result of compression at active margins: mountains in other locations are said to have been caused by the same process but further back in time. This is disproved by the young age of uplift of mountains in intercontinental and passive margin positions. Subduction is supposed to have been continuous for hundreds of millions of years, so fails to explain the world-wide uplifts in just a few million years.
Geomorphologists should be guided by their own findings, and refrain from theory-driven hypotheses of plate collision or landscape evolution.
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Xie, Bo, Shunbing Meng, and Mingming Zhang. "Evolution of Habitat Quality and Its Response to Topographic Gradient Effect in a Karst Plateau: A Case Study of the Key Biodiversity Conservation Project Area of Wuling Mountains." International Journal of Environmental Research and Public Health 20, no. 1 (December 26, 2022): 331. http://dx.doi.org/10.3390/ijerph20010331.
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Habitat quality (HQ) is widely considered to be a proxy indicator for biodiversity. Assessing the dynamic changes in HQ induced by land-use and land-cover (LULC) changes could provide a scientific perspective for regional sustainable development, especially in the ecologically fragile karst plateau mountainous areas. We selected nine landscape metrics to examine LULC dynamics in the Key Biodiversity Conservation Project Area of Wuling Mountains in Guizhou province, China, based on the land-use data for the 1990–2018 period. HQ was evaluated using the InVEST model and the topographic gradient effect on HQ was analyzed using the topographic position index. The results showed that the dominant land categories in the study area were arable land, grassland, and forestland. Land transformation was mainly characterized by a shift from cultivated land to construction land and forestland, and a mutual conversion between grassland and forestland. The changes improved landscape heterogeneity and the degree of fragmentation. The HQ of the study area was high, although exhibited a declining trend from 1990 to 2018. The eastern and western parts had relatively high HQ, whereas the southern and northern parts had low HQ. The topographic gradient had a significant effect on spatial patterns of HQ. High HQ distribution was consistent with that of forestland and was dominant along the topographic gradient, while low HQ distribution was consistent with that of construction land and cultivated land and was dominant along the topographic gradient.
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Cox, Justin A. W., W. James Steenburgh, David E. Kingsmill, Jason C. Shafer, Brian A. Colle, Olivier Bousquet, Bradley F. Smull, and Huaqing Cai. "The Kinematic Structure of a Wasatch Mountain Winter Storm during IPEX IOP3." Monthly Weather Review 133, no. 3 (March 1, 2005): 521–42. http://dx.doi.org/10.1175/mwr-2875.1.
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Abstract The influence of orographic circulations on the precipitation structure of a Wasatch Mountain winter storm is examined using observations collected during the third intensive observing period (IOP3) of the Intermountain Precipitation Experiment (IPEX). The event featured the passage of a midlevel (700–550 hPa) trough followed 3 h later by a surface trough. Prior to and during the midlevel trough passage, large-scale southwesterly flow impinged on the Wasatch Mountains. Low-level confluence was observed between this southwesterly flow and along-barrier southerly flow within 20–40 km of the Wasatch Mountains. This confluence zone, which moved toward the Wasatch Mountains during and following the passage of the midlevel trough, was accompanied by low-level convergence and precipitation enhancement over the upstream lowlands. Dual-Doppler analysis revealed the presence of a shallow along-barrier jet near the base of the Wasatch Mountains that was surmounted by southwesterly cross-barrier flow at mid- and upper-mountain levels. This cross-barrier flow produced strong (1–2 m s−1) ascent as it interacted with the steep windward slopes of the Wasatch Mountains, where precipitation was roughly double that observed in the lowlands upstream. Flow deflection and splitting were also observed near the highest terrain features. A narrow region of strong subsidence, which at times exceeded 2 m s−1, was found to the lee of the Wasatch and, based on radar imagery, appeared to modulate hydrometeor spillover aloft. Processes contributing to the evolution of the near-barrier flow field, including topographic blocking, diabatic effects, and surface friction contrasts, are discussed.
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Ruban, Dmitry A., Anna V. Mikhailenko, and Vladimir A. Ermolaev. "Inverted Landforms of the Western Caucasus: Implications for Geoheritage, Geotourism, and Geobranding." Heritage 5, no. 3 (August 24, 2022): 2315–31. http://dx.doi.org/10.3390/heritage5030121.
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Relief inversion is the result of an unusual interplay between landform evolution and peculiarities of geological settings. Recent fieldwork in Mountainous Adygeya in the western part of the Greater Caucasus mountains has enabled the identification of several inverted landforms. The Gud and Gudok mountains constitute a “classical” inverted landform with the top corresponding to the syncline’s core, which consists of relatively hard Middle Jurassic crinoid limestones. The Kabanya mountain, with the nearby branch of the Skalisty range, has a similar geological setting, although the hard Upper Jurassic carbonates that form the monocline and overlie the syncline also contribute to the preservation of the topographical high above the structural low. The northwestern segment of the Skazhenny range is formed of relatively soft Lower–Middle Jurassic shales, and its inversion results from the protection of the syncline’s core by capping Upper Jurassic carbonates. These landforms represent progressive, transitional, and regressive inversion, respectively. Their relative diversity and significance in local topography allow them to be classified as geomorphosites, i.e., important elements of the geoheritage of Mountainous Adygeya. Each of these has certain touristic potential, and a geotouristic route allowing the comprehension of these geomorphosites from several viewpoints is proposed. Climbing these mountains for closer examination may combine geotourism and adventure tourism. Additionally, the Gud and Gudok landform “symbolizing” the geodiversity of the study area can be used for branding local food products such as cheese, which is popular among visitors.
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Matysek, Marcin, Łukasz Kajtoch, Robert Gwiazda, Bogusław Binkiewicz, and Grzegorz Szewczyk. "Could gaps and diverse topography compensate for habitat deficiency by the forest-dwelling bird Hazel Grouse (Tetrastes bonasia)?" Avian Biology Research 12, no. 2 (March 13, 2019): 59–66. http://dx.doi.org/10.1177/1758155919832190.
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The Hazel Grouse ( Tetrastes bonasia) is considered an indicator of the naturalness and heterogeneity of the forest environment. This species occurs in various woods and forages on a variety of plants. The aim of this study was to verify the hypothesis that, in Norway spruce-dominated forest stands, the Hazel Grouse compensates for habitat poverty using non-forest areas and harsh topography, which deliver food resources and shelter for the birds. We compared 14 environmental and topographic variables in forest patches occupied and unoccupied by the Hazel Grouse in the Tatra Mountains (South Poland). Multivariate modelling showed that crucial factors for Hazel Grouse occurrence in spruce-dominated high-mountain forests were southern or western exposures, the presence of streams or glades and a multilayer forest structure with lower plant species richness in the undergrowth layer. Moreover, this species avoided clearcuts and depended either on wild sites (with a high share of deadwood and treefall gaps in mature stands at higher altitudes) or juvenile stands. The results of our study confirmed that gaps in forests and diverse topography could compensate the Hazel Grouse for habitat deficiency. These findings may be important for effective protection of this species in high-mountain spruce-only dominated forests.
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Jolivet, M., G. Heilbronn, C. Robin, L. Barrier, S. Bourquin, Zh Guo, Y. Jia, L. Guerit, W. Yang, and B. Fu. "Reconstructing the Late Palaeozoic – Mesozoic topographic evolution of the Chinese Tian Shan: available data and remaining uncertainties." Advances in Geosciences 37 (December 17, 2013): 7–18. http://dx.doi.org/10.5194/adgeo-37-7-2013.
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Abstract. The topographic evolution of continents and especially the growth and dismembering of mountain ranges plays a major role in the tectonic evolution of orogenic systems, as well as in regional or global climate changes. A large number of studies have concentrated on the description, quantification and dating of relief building in active mountain ranges. However, deciphering the topographic evolution of a continental area submitted to recurrent tectonic deformation over several hundred millions of years remains a challenge. Here we present a synthesis of the tectonic, geochronological and sedimentological data available on the intracontinental Tian Shan Range to describe its general topographic evolution from Late Palaeozoic to Early Tertiary. We show that this evolution has occurred in two very distinct geodynamic settings, initiating during the Carboniferous in an ocean subduction – continent collision tectonic context before becoming, from Early Permian, purely intra-continental. We show that during most of the Mesozoic, the topography is mostly characterized by a progressive general decrease of the relief. Nonetheless localized, recurrent deformation induced the formation of small-scale reliefs during that period. These deformations were driven by far field effects of possibly several geodynamic processes in a way that still remains to be fully understood.
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STEVENS, DUNCAN M., JACQUELINE BISHOP, and MIKE D. PICKER. "Phylogenetic analysis reveals high local endemism and clear biogeographic breaks in southern African stoneflies (Notonemouridae, Plecoptera)." Zootaxa 4483, no. 3 (September 24, 2018): 428. http://dx.doi.org/10.11646/zootaxa.4483.3.2.
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The low vagility of the southern African Notonemouridae (stoneflies, Plecoptera), and their restriction to temperate montane refugia, make them a useful model for examining the evolution and biogeography of the rich palaeogenic fauna of the region. Here we use maximum parsimony tree reconstruction based on morphological characters and a partial COI mtDNA sequence to explore the evolutionary history and biogeography of the family in southern Africa. Morphological and molecular parsimony cladograms were largely in agreement, and supported monophyly of all six genera in the region. Previously undocumented morphological features in Plecoptera are identified: the first record of paraproct glands, and the presence of paired spermathecae in Aphanicercopsis Barnard females (all other Plecoptera have a single or a divided spermatheca). Some phylogenetically useful characters were the degree of fusion of the ventral abdominal nerve cord ganglia, male paraproct glands (presence and shape), and accessory glands of the male seminal vesicle. Two main biogeographic zones were defined: Eastern Highlands and the Cape Fold Mountains, with an additional outlying zone, the Namaqualand Highlands. Almost 41% of species were endemic to a single mountain range group. The most species-rich region was the intersection of the Southern and Western Cape Fold Mountains. It is hypothesized that, after the separation of Gondwanaland, the common ancestor of the region’s six genera dispersed from a Cape Fold Mountain origin to the Amatola and Drakensberg montane areas of the southern tip of the African continent. The high number of species within the Cape Fold Mountains compared to other mountain ranges in the region is likely a reflection of the topographic complexity of this mountain system and its influence on vicariant events.
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Kerr, Andrew, and Alan Gilchrist. "Glaciation, erosion and the evolution of the Transantarctic Mountains, Antarctica." Annals of Glaciology 23 (1996): 303–8. http://dx.doi.org/10.3189/s0260305500013574.
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Modelling studies of the tectonic evolution of the Transantarctic Mountains in Antarctica have drawn differing conclusions as to the primary mechanisms involved. None has considered the role of the East Antarctic ice sheet in detail. We use a denudation—flexural model to examine the isostatic response of the continental margin to glacial erosion to determine whether glacial processes have played a role in forcing mountain uplift.The conclusion is that, although there are insufficient data formally to delimit the role of glacial erosion, available geophysical and geomorphological data are not inconsistent with the results of the differential denudation model, providing certain conditions are met. These results indicate that the current topography of the Transantarctic Mountains can be simulated, in part, from the isostatic response of the lithosphere to glacial erosion. The short wavelength and high amplitude of the Transantarctic Mountains do not require a low flexural rigidity in the unrated lithosphere, provided there is a fast escarpment retreat from the rift hinge, high escarpment denudation rates and a large differential in denudation between the coastal zone and the interior.
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Kerr, Andrew, and Alan Gilchrist. "Glaciation, erosion and the evolution of the Transantarctic Mountains, Antarctica." Annals of Glaciology 23 (1996): 303–8. http://dx.doi.org/10.1017/s0260305500013574.
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Modelling studies of the tectonic evolution of the Transantarctic Mountains in Antarctica have drawn differing conclusions as to the primary mechanisms involved. None has considered the role of the East Antarctic ice sheet in detail. We use a denudation—flexural model to examine the isostatic response of the continental margin to glacial erosion to determine whether glacial processes have played a role in forcing mountain uplift. The conclusion is that, although there are insufficient data formally to delimit the role of glacial erosion, available geophysical and geomorphological data are not inconsistent with the results of the differential denudation model, providing certain conditions are met. These results indicate that the current topography of the Transantarctic Mountains can be simulated, in part, from the isostatic response of the lithosphere to glacial erosion. The short wavelength and high amplitude of the Transantarctic Mountains do not require a low flexural rigidity in the unrated lithosphere, provided there is a fast escarpment retreat from the rift hinge, high escarpment denudation rates and a large differential in denudation between the coastal zone and the interior.
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Terhune, Patrick J., Jeffrey A. Benowitz, Jeffrey M. Trop, Paul B. O’Sullivan, Robert J. Gillis, and Jeffrey T. Freymueller. "Cenozoic tectono-thermal history of the southern Talkeetna Mountains, Alaska: Insights into a potentially alternating convergent and transform plate margin." Geosphere 15, no. 5 (July 16, 2019): 1539–76. http://dx.doi.org/10.1130/ges02008.1.
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Abstract The Mesozoic–Cenozoic convergent margin history of southern Alaska has been dominated by arc magmatism, terrane accretion, strike-slip fault systems, and possible spreading-ridge subduction. We apply 40Ar/39Ar, apatite fission-track (AFT), and apatite (U-Th)/He (AHe) geochronology and thermochronology to plutonic and volcanic rocks in the southern Talkeetna Mountains of Alaska to document regional magmatism, rock cooling, and inferred exhumation patterns as proxies for the region’s deformation history and to better delineate the overall tectonic history of southern Alaska. High-temperature 40Ar/39Ar thermochronology on muscovite, biotite, and K-feldspar from Jurassic granitoids indicates postemplacement (ca. 158–125 Ma) cooling and Paleocene (ca. 61 Ma) thermal resetting. 40Ar/39Ar whole-rock volcanic ages and 45 AFT cooling ages in the southern Talkeetna Mountains are predominantly Paleocene–Eocene, suggesting that the mountain range has a component of paleotopography that formed during an earlier tectonic setting. Miocene AHe cooling ages within ∼10 km of the Castle Mountain fault suggest ∼2–3 km of vertical displacement and that the Castle Mountain fault also contributed to topographic development in the Talkeetna Mountains, likely in response to the flat-slab subduction of the Yakutat microplate. Paleocene–Eocene volcanic and exhumation-related cooling ages across southern Alaska north of the Border Ranges fault system are similar and show no S-N or W-E progressions, suggesting a broadly synchronous and widespread volcanic and exhumation event that conflicts with the proposed diachronous subduction of an active west-east–sweeping spreading ridge beneath south-central Alaska. To reconcile this, we propose a new model for the Cenozoic tectonic evolution of southern Alaska. We infer that subparallel to the trench slab breakoff initiated at ca. 60 Ma and led to exhumation, and rock cooling synchronously across south-central Alaska, played a primary role in the development of the southern Talkeetna Mountains, and was potentially followed by a period of southern Alaska transform margin tectonics.
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Schwartz, Theresa M., Katharina Methner, Andreas Mulch, Stephan A. Graham, and C. Page Chamberlain. "Paleogene topographic and climatic evolution of the Northern Rocky Mountains from integrated sedimentary and isotopic data." GSA Bulletin 131, no. 7-8 (February 6, 2019): 1203–23. http://dx.doi.org/10.1130/b32068.1.
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Zavala Sansón, L., A. C. Barbosa Aguiar, and G. J. F. van Heijst. "Horizontal and vertical motions of barotropic vortices over a submarine mountain." Journal of Fluid Mechanics 695 (February 8, 2012): 173–98. http://dx.doi.org/10.1017/jfm.2012.9.
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AbstractThe evolution of barotropic vortices over a topographic, axisymmetric mountain in a homogeneous rotating fluid is studied experimentally. The aim is to identify the main physical processes observed in (i) a horizontal plane of motion, perpendicular to the rotation axis of the system, and (ii) a vertical plane across the diameter of the mountain. The vortices are monopolar cyclones initially generated near or over the topography. Initially, the vortices drift towards the mountain due to the $\ensuremath{\beta} $-effect associated with the topographic slope. On arriving, they turn around the obstacle in an anticyclonic direction, whilst anticyclonic vorticity is generated over the summit. The long-term vorticity distribution is dominated by the original cyclone elongated around the topographic contours and the generated anticyclone over the tip of the topography. In the vertical plane an oscillatory uphill–downhill flow is generated, which is directly related to the drift of the cyclone around the mountain. Depending on the vortex characteristics, the period of the oscillation ranges from 4 to 10 times the rotation period of the system. The horizontal and vertical flow fields are reproduced numerically by using a shallow-water formulation, which allows a detailed view of the vertical motions, hence facilitating the interpretation of the experimental results. In addition, the cyclone–anticyclone pair over the mountain is compared with analytical solutions of topographically trapped waves. A general conclusion is that vertical motions persist for several days (or rotation periods), which implies that this mechanism might be potentially important for the vertical transport over seamounts.
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Noetzli, J., and S. Gruber. "Transient thermal effects in Alpine permafrost." Cryosphere 3, no. 1 (April 27, 2009): 85–99. http://dx.doi.org/10.5194/tc-3-85-2009.
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Abstract. In high mountain areas, permafrost is important because it influences the occurrence of natural hazards, because it has to be considered in construction practices, and because it is sensitive to climate change. The assessment of its distribution and evolution is challenging because of highly variable conditions at and below the surface, steep topography and varying climatic conditions. This paper presents a systematic investigation of effects of topography and climate variability that are important for subsurface temperatures in Alpine bedrock permafrost. We studied the effects of both, past and projected future ground surface temperature variations on the basis of numerical experimentation with simplified mountain topography in order to demonstrate the principal effects. The modeling approach applied combines a distributed surface energy balance model and a three-dimensional subsurface heat conduction scheme. Results show that the past climate variations that essentially influence present-day permafrost temperatures at depth of the idealized mountains are the last glacial period and the major fluctuations in the past millennium. Transient effects from projected future warming, however, are likely larger than those from past climate conditions because larger temperature changes at the surface occur in shorter time periods. We further demonstrate the accelerating influence of multi-lateral warming in steep and complex topography for a temperature signal entering the subsurface as compared to the situation in flat areas. The effects of varying and uncertain material properties (i.e., thermal properties, porosity, and freezing characteristics) on the subsurface temperature field were examined in sensitivity studies. A considerable influence of latent heat due to water in low-porosity bedrock was only shown for simulations over time periods of decades to centuries. At the end, the model was applied to the topographic setting of the Matterhorn (Switzerland). Results from idealized geometries are compared to this first example of real topography, and possibilities as well as limitations of the model application are discussed.
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Cochran, William J., James A. Spotila, and Philip S. Prince. "Incipient evolution of the Eastern California shear zone through the transpressional zone of the San Bernardino Mountains and San Gorgonio Pass, California." Geosphere 16, no. 4 (June 5, 2020): 919–35. http://dx.doi.org/10.1130/ges02121.1.
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Abstract The nature of the connection between the Eastern California shear zone (ECSZ) and the San Andreas fault (SAF) in southern California (western United States) is not well understood. Northwest of San Gorgonio Pass, strands of the ECSZ may be migrating south and west into the convergent zone of the San Bernardino Mountains (SBM) as it is advected to the southeast via the SAF. Using high-resolution topography and field mapping, this study aims to test whether diffuse faults within the SBM represent a nascent connection between the ECSZ and the SAF. Topographic resolution of ≤1 m was achieved using both lidar and unmanned aerial vehicle surveys along two Quaternary strike-slip faults. The Lone Valley fault enters the SBM from the north and may form an along-strike continuation of the Helendale fault. We find that its geomorphic expression is obscured where it crosses Quaternary alluvium, however, suggesting that it may have a low rate of yet-undetermined activity. The Lake Peak fault is located farther south and cuts through the high topography of the San Gorgonio massif and may merge with strands of the SAF system. We find that this fault clearly cuts Quaternary glacial deposits, although the magnitude of offset is difficult to assess. Based on our interpretation of geomorphic features, we propose that the Lake Peak fault has predominantly dextral or oblique-dextral motion, possibly with a slip rate that is comparable to the low rates observed along other strands of the ECSZ (i.e., ≤1 mm/yr). Comparing the geomorphic expressions of these faults is difficult, however, given that the erosive nature of the mountainous landscape in the SBM may obscure evidence of active faulting. Based on these observations, as well as the occurrence of other diffuse faults in the region, we suggest that dextral strain is overprinting the actively convergent zone of the SBM, thereby creating a throughgoing connection between the ECSZ and the SAF west of San Gorgonio Pass.
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Schumacher, Russ S., David M. Schultz, and John A. Knox. "Influence of Terrain Resolution on Banded Convection in the Lee of the Rocky Mountains." Monthly Weather Review 143, no. 4 (March 31, 2015): 1399–416. http://dx.doi.org/10.1175/mwr-d-14-00255.1.
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Abstract On 16–17 February 2007, snowbands formed in the lee of the Rocky Mountains in Wyoming, Colorado, and Nebraska on the anticyclonic-shear side of a midlevel jet streak. Two types of bands were prevalent: a longer, wider band associated with frontogenesis along an equatorward-moving cold front (major band) and multiple shorter, narrower bands farther poleward (minor bands). To understand how the upstream terrain affected the occurrence and intensity of the bands, multiple mesoscale model simulations were performed in which the terrain was incrementally smoothed. The evolutions of the synoptic patterns were similar in all simulations that included topography, but the synoptic pattern differed and no bands developed in a simulation with a flat land surface. These results allowed a focus on the changes to the banded precipitation due to the terrain resolution. Remarkably, although the exact location of the bands differed from run to run, the bands in all simulations with topography were in roughly the same region where they occurred on 16–17 February 2007. The major band was associated with frontogenesis along an equatorward-moving cold front that became stalled against the terrain. The minor bands formed from the release of conditional, symmetric, and inertial instabilities by ascent up the large-scale topography, rather than by ascent up specific small-scale topographic features. Because the bands were not tied to specific terrain features, these results suggest that the precise location of the minor bands is unpredictable.
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Zhang, Yu, Jie Min, Chunxia Liu, and Yuechen Li. "Hotspot Detection and Spatiotemporal Evolution of Catering Service Grade in Mountainous Cities from the Perspective of Geo-Information Tupu." ISPRS International Journal of Geo-Information 10, no. 5 (April 30, 2021): 287. http://dx.doi.org/10.3390/ijgi10050287.
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Catering services are an essential part of urban life. The spatial structure and evolution of catering services can reflect the characteristics of an urban structure to a certain extent. In this study, we selected the main urban area of Chongqing, a typical mountainous city, as the research area. According to data sources for 200,000 catering POI data points in 2015 and 2020, we extracted the hotspots according to catering service grade based on kernel density. We quantitatively analyzed the spatiotemporal structure of catering services in the mountainous city. In addition, we used digital field hierarchical structure Tupu and generalized symmetric structure Tupu to identify the spatial morphology and evolution characteristics to enhance the understanding of geoscience trends. The results showed that (1) the distribution of catering services was statically consistent with the “multi-center group” distribution of the mountainous city and dynamically similar to the “sprawling leap” development of the mountainous city where it developed from independent points to cross mountains and rivers. Moreover, we found that there was a tendency of adhering development between groups. (2) From the perspective of symmetrical distribution, the symmetrical distribution of the catering industry reflected a certain generalized symmetrical structure with mountains and rivers in the mountainous city. Furthermore, the city tended to develop symmetrically along the topography, thus forming the symmetry of economic geography.
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Bishop, Michael P., Andrew B. G. Bush, Luke Copland, Ulrich Kamp, Lewis A. Owen, Yeong B. Seong, and John F. Shroder. "Climate Change and Mountain Topographic Evolution in the Central Karakoram, Pakistan." Annals of the Association of American Geographers 100, no. 4 (August 31, 2010): 772–93. http://dx.doi.org/10.1080/00045608.2010.500521.
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Andreani, L., and R. Gloaguen. "Geomorphic analysis of transient landscapes in the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American–Caribbean–Cocos plate boundary." Earth Surface Dynamics 4, no. 1 (January 21, 2016): 71–102. http://dx.doi.org/10.5194/esurf-4-71-2016.
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Abstract. We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. We intend to characterize and understand the complex tectonic setting that produced an intricate pattern of landscapes using tectonic geomorphology, as well as available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in a transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low-amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes. Lower reaches adjust to new base-level conditions and are characterized by multiple knickpoints. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos forearc sliver and (2) the compression along the northern tip of the Central American volcanic arc. Although most of the shortening between the Cocos forearc sliver and the North American Plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén Basin.
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Andreani, L., and R. Gloaguen. "Geomorphic analysis of transient landscapes from the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American–Caribbean–Cocos plate boundary." Earth Surface Dynamics Discussions 3, no. 3 (September 15, 2015): 941–1003. http://dx.doi.org/10.5194/esurfd-3-941-2015.
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Abstract. We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. The complex tectonic setting produced an intricate pattern of landscapes that we try to systemize using remote sensing tectonic geomorphology and available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes while lower segments characterized by multiple knickpoints, that adjust to new base-level conditions. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos fore-arc sliver, and (2) the compression along the northern tip of the Central America Volcanic Arc. Although most of the shortening between the Cocos fore-arc sliver and the North American plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén basin.
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Cai, Shun, Hao-peng Geng, Bao-tian Pan, Yang Hong, and Li-ping Chen. "Topographic controls on the annual runoff coefficient and implications for landscape evolution across semiarid Qilian Mountains, NE Tibetan Plateau." Journal of Mountain Science 17, no. 2 (February 2020): 464–79. http://dx.doi.org/10.1007/s11629-019-5584-7.
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Chen, W., Y. Li, Y. Liu, S. Liu, and B. Yue. "Complex topographic configuration in the Hengduan Mountains shaped the phylogeographic structure of Chinese white-bellied rats." Journal of Zoology 284, no. 3 (March 9, 2011): 215–23. http://dx.doi.org/10.1111/j.1469-7998.2011.00797.x.
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Badgley, Catherine, and John A. Finarelli. "Diversity dynamics of mammals in relation to tectonic and climatic history: comparison of three Neogene records from North America." Paleobiology 39, no. 3 (2013): 373–99. http://dx.doi.org/10.1666/12024.
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In modern ecosystems, regions of topographic heterogeneity, when compared with nearby topographically homogeneous regions, support high species densities of mammals and other groups. This biogeographic pattern could be explained by either greater diversification rates or greater accommodation of species in topographically complex regions. In this context, we assess the hypothesis that changes in landscape history have stimulated diversification in mammals. Landscape history includes tectonic and climatic processes that influence topographic complexity at regional scales. We evaluated the influence of changes in topographic complexity and climate on origination and extinction rates of rodents, the most diverse clade of mammals.We compared the Neogene records of rodent diversity for three regions in North America. The Columbia Basin of the Pacific Northwest (Region 1) and the northern Rocky Mountains (Region 2) were tectonically active over much of the Cenozoic and are characterized by high topographic complexity today. The northern Great Plains (Region 3) have been tectonically quiescent, with low relief, throughout the Cenozoic. These three regions have distinctive geologic histories and substantial fossil records. All three regions showed significant changes in diversification and faunal composition over the Neogene. In the montane regions, originations and extinctions peaked at the onset and close, respectively, of the Miocene Climatic Optimum (17–14 Ma), with significant changes in faunal composition accompanying these episodes of diversification. In the Great Plains, rodents showed considerable turnover but infrequent diversification. Peak Neogene diversity in the Great Plains occurred during cooling after the Miocene Climatic Optimum. These histories suggest that climatic changes interacting with increasing topographic complexity intensify macroevolutionary processes. In addition, close tracking of diversity and fossil productivity with the stratigraphic record suggests either large-scale sampling biases or the mutual response of diversity and depositional processes to changes in landscape history.
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Lemly, Joanna M., and David J. Cooper. "Multiscale factors control community and species distribution in mountain peatlands." Botany 89, no. 10 (October 2011): 689–713. http://dx.doi.org/10.1139/b11-040.
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We studied the vegetation of 166 fens in Yellowstone National Park, USA, to determine the relationship between species distribution in mountain peatlands and regional-, landscape-, and local-scale environmental variables. Plant communities were identified through hierarchical agglomerative cluster analysis, patterns in species distribution were explored using nonmetric multidimensional scaling, and the relative importance of variables was assessed though partial canonical correspondence analysis. Five major bedrock types influenced groundwater feeding fens: three volcanic types, a glacial till complex, and rock altered by acidic geothermal activity. Ionic concentrations generally increased with pH, but acidic geothermal fens had very low pH and high electrical conductivity. Bryophyte distribution was controlled by groundwater chemistry, while vascular plants responded to a broader range of variables. When partitioned by spatial scale, landscape variables accounted for >60% of the variation explained. When partitioned categorically, geochemical and topographic variables were more important than geographic factors. For fens in mountainous regions, the primary gradient is site-level water chemistry, which is strongly linked to regional bedrock geology. Site- and stand-level topography represent a secondary gradient. Most mountain fens fit within the established poor–rich gradient; however, geochemical acid production creates a distinct category outside the conventional paradigm.
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Adhikari, S., and S. J. Marshall. "Influence of high-order mechanics on simulation of glacier response to climate change: insights from Haig Glacier, Canadian Rocky Mountains." Cryosphere Discussions 7, no. 2 (April 24, 2013): 1707–48. http://dx.doi.org/10.5194/tcd-7-1707-2013.
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Abstract. Evolution of glaciers in response to climate change has mostly been simulated using simplified dynamical models. Because these models do not account for the influence of high-order physics, corresponding results may exhibit some biases. For Haig Glacier in the Canadian Rocky Mountains, we test this hypothesis by comparing simulation results obtained from 3-D numerical models that deal with different assumptions concerning ice-flow physics, ranging from simple shear-deformation to comprehensive Stokes flow. In glacier retreat scenarios, we find a minimal role of high-order mechanics in glacier evolution, as geometric effects at our site (the presence of an overdeepened bed) result in limited horizontal movement of ice (flow speed on the order of a few meters per year). Consequently, high-order and reduced models all predict that Haig Glacier ceases to exist by ca. 2080 under ongoing climate warming. The influence of high-order mechanics is evident, however, in glacier advance scenarios, where ice speeds are greater and ice dynamical effects become more important. To generalize these findings for other glacier applications, we advise that high-order mechanics are important and therefore should be considered while modelling the evolution of active glaciers. Reduced model predictions may, however, be adequate for other glaciologic and topographic settings, particularly where flow speeds are low.
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Fernández-Lozano, J., G. Gutiérrez-Alonso, E. Willingshofer, D. Sokoutis, G. de Vicente, and S. Cloetingh. "Shaping of intraplate mountain patterns: The Cantabrian orocline legacy in Alpine Iberia." Lithosphere 11, no. 5 (August 2, 2019): 708–21. http://dx.doi.org/10.1130/l1079.1.
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Abstract The present-day topography in Iberia is related to geodynamic processes dealing with lithospheric-scale deformation. However, little attention has been paid to the role of inherited crustal- or lithospheric-scale structures involved in the recent observed large-scale topographic patterns. Whereas the analysis of brittle structures focuses on the evolution of Mesozoic sedimentary basins and their subsequent response to tectonic inversion, their contribution to mountain building has been underestimated. Large numbers of structures, from ductile to brittle, which affected the whole lithosphere, were developed during the evolution of the Cantabrian orocline (ca. 310–300 Ma). The contribution of these Paleozoic post-Variscan structures, together with lithospheric mantle evolution and replacement during orocline development in the Mesozoic and Cenozoic geological evolution of Iberia, remains unexplored. To explore the role of these inherited structures on the final configuration of topography during N-S Pyrenean shortening, we carried out a series of analogue experiments complemented by surface velocity field analyses. Our experiments indicate that strain was concentrated along preexisting crustal- to lithospheric-scale discontinuities, and they show several reactivation events marked by differences in the velocity vector field. Differences in fault displacement were also observed in the models depending upon preexisting fault trends. The obtained results may explain the different amount of displacement observed during the reactivation of some of the post-orocline structures in Iberia during the Cenozoic, indicating the key role of unveiled structures, which probably have accommodated most of the Alpine shortening.
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Lv, Mingyang, Huadong Guo, Xiancai Lu, Guang Liu, Shiyong Yan, Zhixing Ruan, Yixing Ding, and Duncan J. Quincey. "Characterizing the behaviour of surge- and non-surge-type glaciers in the Kingata Mountains, eastern Pamir, from 1999 to 2016." Cryosphere 13, no. 1 (January 24, 2019): 219–36. http://dx.doi.org/10.5194/tc-13-219-2019.
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Abstract. Glaciers in the Pamir Mountains are generally acknowledged to be in a stable state and show the least glacial retreat in high-mountain Asia; however, they are also some of the most dynamic glaciers in the region and their behaviour has been spatially variable in recent decades. Few data exist for these glaciers, in particular relating to how they are responding to recent climatic changes. Here, we utilize Landsat 7 (ETM+), Landsat 8 (OLI), ASTER, and Google Earth optical images acquired between 1999 and 2016 to characterize the dynamics of the glaciers in the Kingata Mountains, located in the eastern Pamir Mountains. We quantify the velocity, areal, and frontal changes of these glaciers, which provide us with valuable data on their recent dynamic evolution and an indication of how they may evolve in future years. We highlight 28 glaciers among which 17 have changed markedly over the study period. We identify four advancing glaciers and 13 surge-type glaciers. The dynamic evolution of the glacier surges shows some similarity with those of the nearby Karakoram, suggesting that both hydrological and thermal controls are important for surge initiation and recession. Topography seems to be a dominant control on non-surge glacier behaviour in the Kingata Mountains, with the north side of the divide characterized by steep, avalanche-fed basins and glacier tongues now approaching recession in contrast to those on the south side of the divide that capture the majority of precipitation and have much broader plateau-like accumulation zones. This study is the first synthesis of glacial motion across this region and provides a baseline with which to compare future changes.
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Heineke, Caroline, Ralf Hetzel, Nils-Peter Nilius, Christoph Glotzbach, Cüneyt Akal, Marcus Christl, and Andrea Hampel. "Spatial patterns of erosion and landscape evolution in a bivergent metamorphic core complex revealed by cosmogenic 10Be: The central Menderes Massif (western Turkey)." Geosphere 15, no. 6 (September 30, 2019): 1846–68. http://dx.doi.org/10.1130/ges02013.1.
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Abstract In extensional provinces with low-angle normal faulting (such as the Aegean region), both tectonic processes and erosion induce landscape change, but their interaction during the evolution of topography and relief accompanying continental extension has rarely been addressed. Here we present local and catchment-wide 10Be erosion rates that document the spatial pattern of erosion in the central Menderes Massif, a metamorphic core complex consisting of two asymmetric mountain ranges (Bozdağ and Aydın) bound by detachment faults and active grabens. Catchment-wide erosion rates on the northern flank of the Bozdağ Range are rather low (40–110 mm/k.y.) but reach values of >300 mm/k.y. on the steep southern escarpment—a pattern that reflects both topography and bedrock lithology. In the Aydın Range, erosion rates are generally higher, with mean erosion rates of ∼190 and ∼260 mm/k.y. on the northern and southern flank, respectively, and more variable along strike. In both ranges, erosion rates of ridge crests derived from amalgamated clasts are 30–90 mm/k.y. The difference between local and catchment-wide erosion rates indicates that topographic relief increases in most parts of the massif in response to ongoing fault-related uplift and concomitant river incision. Our findings document that tectonic processes exert a significant control on landscape evolution during active continental extension and are reflected in both the topographic signature and the spatial pattern of erosion. In the Menderes Massif, rock susceptibility to weathering and erosion is a dominant factor that controls the erosional contribution to rock exhumation, which varies spatially between ∼10% and ∼50%.
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Kaushik, S., L. Ravanel, F. Magnin, Y. Yan, E. Trouve, and D. Cusicanqui. "DISTRIBUTION AND EVOLUTION OF ICE APRONS IN A CHANGING CLIMATE IN THE MONT-BLANC MASSIF (WESTERN EUROPEAN ALPS)." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B3-2021 (June 28, 2021): 469–75. http://dx.doi.org/10.5194/isprs-archives-xliii-b3-2021-469-2021.
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Abstract. Ice Apron (IA) is a poorly studied ice feature, commonly existing in all the world’s major mountain regions. This study aims to map the locations of the IAs in the Mont Blanc massif (MBM), making use of the very high-resolution optical satellite images from 2001, 2012 and 2019. 423 IAs were identified and accurately delineated in the MBM on the images from 2019, and their topographic characteristics were studied. We generated our own Digital Elevation Model (DEM) at 4 m resolution since the freely available products predominantly suffer from significant inconsistencies, especially in steep mountain areas. Results show that most IAs exist at elevations above the regional Equilibrium Line Altitude (ELA), on steep slopes, on concave surfaces, on northern and southern aspects and on the most rugged terrains. They are also commonly associated with steep slope glaciers as 85% of them occur on these glaciers’ headwalls. A comparison between 2001 and 2019 shows that IAs have lost around 29% of their area over a period of 18 years. This is significant and the rate of area loss is very alarming in comparison with the larger glacier bodies. We also studied the effect of topographic parameters on the area loss. We found that topographic factors like slope, aspect, curvature, elevation and Terrain Ruggedness Index (TRI) strongly influence the rate of area loss of IAs.
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Adhikari, S., and S. J. Marshall. "Influence of high-order mechanics on simulation of glacier response to climate change: insights from Haig Glacier, Canadian Rocky Mountains." Cryosphere 7, no. 5 (September 25, 2013): 1527–41. http://dx.doi.org/10.5194/tc-7-1527-2013.
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Abstract. Evolution of glaciers in response to climate change has mostly been simulated using simplified dynamical models. Because these models do not account for the influence of high-order physics, corresponding results may exhibit some biases. For Haig Glacier in the Canadian Rocky Mountains, we test this hypothesis by comparing simulation results obtained from 3-D numerical models that deal with different assumptions concerning physics, ranging from simple shear deformation to comprehensive Stokes flow. In glacier retreat scenarios, we find a minimal role of high-order mechanics in glacier evolution, as geometric effects at our site (the presence of an overdeepened bed) result in limited horizontal movement of ice (flow speed on the order of a few meters per year). Consequently, high-order and reduced models all predict that Haig Glacier ceases to exist by ca. 2080 under ongoing climate warming. The influence of high-order mechanics is evident, however, in glacier advance scenarios, where ice speeds are greater and ice dynamical effects become more important. Although similar studies on other glaciers are essential to generalize such findings, we advise that high-order mechanics are important and therefore should be considered while modeling the evolution of active glaciers. Reduced model predictions may be adequate for other glaciologic and topographic settings, particularly where flow speeds are low and where mass balance changes dominate over ice dynamics in determining glacier geometry.
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Zavala, Valeria, Sébastien Carretier, and Stéphane Bonnet. "Influence of orographic precipitation on the topographic and erosional evolution of mountain ranges." Basin Research 32, no. 6 (April 2, 2020): 1574–99. http://dx.doi.org/10.1111/bre.12443.
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Djurovic, Predrag, Aleksandar Petrovic, and Sava Simic. "The overall impact of Pleistocene glaciation on morphological diversity of uvalas at Durmitor and Zijovo." Glasnik Srpskog geografskog drustva 90, no. 1 (2010): 17–34. http://dx.doi.org/10.2298/gsgd1001017d.
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The alternation of glacial and carts processes as the consequence of frequent changes of glacial and interglacial phases could be recognized at the mountains Durmitor and Zijovo. Re-modeling of glacial morphology (cirques and trough valleys) carved currently karst topography with domination of uvalas. Their size and shape vary considerably as the consequence of differences within the preexisting glacial forms. Duration and intensity of kartification, which re-modeled former glacial forms into karst landforms, determine the degree of uvalas development and formation of three distinct evolution types of high-mountainous uvalas: glacial, glacial-karst and glaciofluvial. .
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László, Csontos, Sasvári Ágoston, Pocsai Tamás, Kósa László, Azad T. Salae, and Ali Athar. "Structural evolution of the northwestern Zagros, Kurdistan Region, Iraq: Implications on oil migration." GeoArabia 17, no. 2 (April 1, 2012): 81–116. http://dx.doi.org/10.2113/geoarabia170281.
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ABSTRACT The studied area in Kurdistan Region of Iraq lies across an important topographic/structural boundary between the southern lowlands and the northern, folded and imbricated Zagros Mountains. It also encompasses a prominent change in structural orientation of the northern Zagros, from a general NW-SE “Zagros” to an E-W “Taurus” trend. Geological mapping and structural observations, both in the mountains (Mesozoic–Palaeogene) and in the lowlands (Neogene), led to the following conclusions. (1) The oldest recorded deformation is a layer-parallel shortening, coupled with southwest-vergent shear that was followed by major folding of ca. 10 km wavelength and ca. 1,000 m amplitude. Even the Upper Miocene–Pliocene Bakhtiari Formation has steep to overturned beds in some parts, and synclines preserve syn-tectonic strata of Neogene–Pliocene age. Box folding is associated with crestal collapse, internal thrusting in the core and with formation of systematic joint sets. (2) On the southern limb of the major folds, thrusting of variable offset can be observed. The thrusts on the southern and northern limbs are considered responsible for the major uplift during main folding. (3) En-échelon fold-relay patterns suggest left-lateral shear along the EW-oriented segment and right-lateral shear along the NW-oriented segment. (4) A quick-look qualitative analysis of striated fault planes suggests a variable shortening trend from NE-SW to N-S, and some rare NW-SE shortening all associated with thrust faults. (5) The general structural setting of the area is linked to the north-eastwards to northwards propagation of the Arabian Margin beneath Eurasia. The ca. 30° bend in the mountain chain may be explained by the original shape of the Arabian Margin, or by pre-existing tectonic zones of E-W orientation in the northern part. Several observations suggest that there was no oroclinal bending (i.e. major rotation) of different parts of the chain, but the structures simply molded on their local buttress (almost) according to present orientations. However, a limited amount of rigid-body rotation in the different segments cannot be ruled out. The changing shortening directions generated several structural combinations on both the NW-SE Zagros and the E-W Taurus segments of the arc, many of which are still preserved. (6) Spectacular bitumen seepage in Upper Cretaceous and Palaeocene limestone originates from fractures or geodes of these formations. Many of these bitumen-filled voids are linked to the above-described Late Neogene–Recent shortening-folding process; therefore hydrocarbon migration into these voids is interpreted to be very young. This contradicts earlier ideas about massive Late Cretaceous breaching and bleeding off of hydrocarbons in this region.
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Novikmec, Milan, Marek Svitok, Dušan Kočický, Ferdinand Šporka, and Peter Bitušík. "Surface Water Temperature and Ice Cover of Tatra Mountains Lakes Depend on Altitude, Topographic Shading, and Bathymetry." Arctic, Antarctic, and Alpine Research 45, no. 1 (February 2013): 77–87. http://dx.doi.org/10.1657/1938-4246-45.1.77.
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Danišík, Martin, Milan Kohút, Igor Broska, and Wolfgang Frisch. "Thermal evolution of the Malá Fatra Mountains (Central Western Carpathians): insights from zircon and apatite fission track thermochronology." Geologica Carpathica 61, no. 1 (February 1, 2010): 19–27. http://dx.doi.org/10.2478/v10096-009-0041-0.
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Thermal evolution of the Malá Fatra Mountains (Central Western Carpathians): insights from zircon and apatite fission track thermochronologyWe apply zircon and apatite fission track thermochronology (ZFT and AFT, respectively) to the Variscan crystal-line basement of the Malá Fatra Mts (Central Western Carpathians) in order to constrain the thermal history. The samples yielded three Early Cretaceous ZFT ages (143.7±9.6, 143.7±8.3, 135.3±6.9 Ma) and one Eocene age (45.2±2.1 Ma), proving that the basement was affected by a very low-grade Alpine metamorphic overprint. Although the precise timing and mechanisms of the overprint cannot be unequivocally resolved, we propose and discuss three alternative explanations: (i) a Jurassic/Cretaceous thermal event related to elevated heat flow associated with extensional tectonics, (ii) early Late Cretaceous thrusting and/or (iii) an Eocene orogeny. Thermal modelling of the AFT cooling ages (13.8±1.4 to 9.6±0.6 Ma) revealed fast cooling through the apatite partial annealing zone. The cooling is interpreted in terms of exhumation of the basement and creation of topographic relief, as corroborated by the sedimentary record in the surrounding Neogene depressions. Our AFT results significantly refine a general exhumation pattern of basement complexes in the Central Western Carpathians. A younging of AFT ages towards the orogenic front is evident, where all the external massifs located closest to the orogenic front (including Malá Fatra Mts) were exhumed after ~13 Ma from temperatures above ~120 °C.
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Tai, Sheng-Lun, Yu-Chieng Liou, Juanzhen Sun, and Shao-Fan Chang. "The Development of a Terrain-Resolving Scheme for the Forward Model and Its Adjoint in the Four-Dimensional Variational Doppler Radar Analysis System (VDRAS)." Monthly Weather Review 145, no. 1 (January 1, 2017): 289–306. http://dx.doi.org/10.1175/mwr-d-16-0092.1.
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Abstract The four-dimensional Variational Doppler Radar Analysis System (VDRAS) developed at the National Center for Atmospheric Research (NCAR) is significantly improved by implementing a terrain-resolving scheme to its forward model and adjoint based on the ghost cell immersed boundary method (GCIBM), which allows the topographic effects to be considered without the necessity to rebuild the model on a terrain-following coordinate system. The new system, called IBM_VDRAS, is able to perform forward forecast and backward adjoint model integration over nonflat lower boundaries, ranging from mountains with smooth slopes to buildings with sharp surfaces. To evaluate the performance of the forward model over complex terrain, idealized numerical experiments of a two-dimensional linear mountain wave and three-dimensional leeside vortices are first conducted, followed by a comparison with a simulation by the Weather Research and Forecasting (WRF) Model. An observing system simulation experiment is also conducted with the assimilation of simulated radar data to examine the ability of IBM_VDRAS in analyzing orographically forced moist convection. It is shown that the IBM_VDRAS can retrieve terrain-influenced three-dimensional meteorological fields including winds, thermodynamic, and microphysical parameters with reasonable accuracy. The new system, with the advanced radar data assimilation capability and the GCIBM terrain scheme, has the potential to be used for studying the evolution of convective weather systems under the influence of terrain.
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Waigwa, Antony N., Brian Njoroge Mwangi, Gituru R. Wahiti, Fred Omengo, Yadong Zhou, and Qingfeng Wang. "Variation of morphological and leaf stoichiometric traits of two endemic species along the elevation gradient of Mount Kenya, East Africa." Journal of Plant Ecology 13, no. 6 (December 1, 2020): 785–92. http://dx.doi.org/10.1093/jpe/rtaa067.
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Abstract Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical mountains. Methods In this study, we assessed the variation of the morphological traits, including plant height, leaf area, leaf thickness, leaf dry weight, specific leaf area and the leaf stoichiometry traits nitrogen, carbon and phosphorous of the two endemic species D. keniensis and L. gregoriana. We further explored the relations of these morphological traits to soil organic carbon, soil total nitrogen, soil phosphorous, annual mean temperature, annual mean precipitation, annual total solar radiation, water vapor pressure and the topographic variables aspect, slope and hill shade along the elevation gradient. Ninety 10 m × 10 m sampling plots were set up along the elevation gradient ranging from 3500 to 4300 m. We used 1 km × 1 km grid cells to rasterize our study area in ArcGIS 10.5 for easy access to data pertaining to the climate of each elevation band. We performed linear regression of the morphological and leaf stoichiometric traits with elevation as explanatory variable. We conducted correlation analysis on the morphological and leaf stoichiometric traits with climatic, soil and topographic variables along the elevation gradient. Important Findings Dendrosenecio keniensis had wool-like pubescent leaves while L. gregoriana had mucilage packed succulent and waxy cuticle leaves to avoid freezing. Both species exhibited reduced metabolic rates as shown by the low leaf phosphorous content. Our results also showed that changes in morphology and leaf stoichiometry were determined by a combination of climate, soil and topographic variables that change along elevation on Mount Kenya. The observed variations in the morphological and leaf stoichiometric traits of D. keniensis and L. gregoriana, which grow side by side along the elevation gradient, were interpreted as adaptation to the harsh environmental conditions.
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Zhong, Cheng, Yiming Bei, Hongliang Gu, and Pengfei Zhang. "Spatiotemporal Evolution of Ecosystem Services in the Wanhe Watershed Based on Cellular Automata (CA)-Markov and InVEST Models." Sustainability 14, no. 20 (October 16, 2022): 13302. http://dx.doi.org/10.3390/su142013302.
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The evaluation of habitat quality and its genesis is of great significance to ecological protection of the watershed. Based on land use data, Digital Elevation Model (DEM), and road network data and population data, the Cellular Automata (CA)-Markov model and InVEST model were used to analyzed the land use change in the Wanhe Watershed, predicting the land use in 2025. Based on this, the degree of the habitat degradation and habitat quality in 2000, 2005, 2010, 2015, 2020, and 2025 were predicted and analyzed, and combined with the particularity of the terrain in the study area, the topography was introduced. Landform relief gradient was used to discuss the relationship between habitat quality and topographic factors in the Wanhe Watershed, and to reveal the distribution law. The result shows that from 2000 to 2025, farmland and forestland are the main land use types in the study area, and the main change is due to the expansion of the construction land, whereby the area increased by 62.86 km2, with an increase of 34.41%, mainly from farmland and forestland. From 2000 to 2020, mainly due to the expansion in urban land and the reduction in forestland, the habitat degradation tends to be serious, and the habitat quality generally shows a downward trend, with areas with low habitat quality having had the largest increase from 452.67 km² in 2000 to 526.15 km² in 2025. The topography of the study area affects the distribution of natural landscapes and the intensity of human activities, resulting in significant differences in the landscape pattern of habitat degradation and habitat quality. The western mountains are relatively better. After 2020, due to the implementation of environmental protection policies, the habitat quality has tended to improve. This study can promote the adjustment of land use planning policies in the study area, maintain the biodiversity in the watershed, and realize the coordinated development of environmental benefits and social and economic development. The research results have theoretical significance and practical value for ecological environmental protection and land use layout in Wanhe Watershed.
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Tai, Sheng-Lun, Yu-Chieng Liou, Shao-Fan Chang, and Juanzhen Sun. "The Heavy Rainfall Mechanism Revealed by a Terrain-Resolving 4DVar Data Assimilation System—A Case Study." Monthly Weather Review 148, no. 6 (May 7, 2020): 2307–30. http://dx.doi.org/10.1175/mwr-d-19-0244.1.
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Abstract In this research a newly developed terrain-resolving four-dimensional variational (4DVar)-based data assimilation system, Immersed Boundary Method_Variational Doppler Radar Analysis System (IBM_VDRAS), is applied to investigate the mechanisms leading to a heavy precipitation event that occurred in Taiwan during the Southwesterly Monsoon Experiment (SoWMEX) conducted in 2008. The multivariate analyses using IBM_VDRAS and surface observations reveal that the warm and moist southwesterly flow from the ocean decelerates after making landfall, forming a surface convergence zone along the coast, which is further strengthened during the passage of a prefrontal rainband. The flow ascends as it advances inland until reaching the mountains, producing persistent precipitation and the enhancement of evaporative cooling as well as a widespread high pressure zone. A very shallow (<0.4 km) layer of offshore flow can be identified over the southwestern plain, which helps to generate a quasi-stationary convergence zone near the coast. Sensitivity studies are carried out to quantify the relative importance of the contributions made by topographic blockage, evaporative cooling, and their nonlinear interaction, to the evolution of this type of convective system. The influence of the topography is identified as the dominant factor in modulating the flow structure of the rainfall system. However, it is the nonlinear interaction between terrain and evaporation that determines the distribution of the temperature and pressure fields.
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Tang, Brian, Matthew Vaughan, Ross Lazear, Kristen Corbosiero, Lance Bosart, Thomas Wasula, Ian Lee, and Kevin Lipton. "Topographic and Boundary Influences on the 22 May 2014 Duanesburg, New York, Tornadic Supercell." Weather and Forecasting 31, no. 1 (February 1, 2016): 107–27. http://dx.doi.org/10.1175/waf-d-15-0101.1.
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Abstract The 22 May 2014 Duanesburg, New York, supercell produced an enhanced Fujita scale category 3 (EF3) tornado and 10-cm-diameter hail. The synoptic setup for the event was ambiguous compared to other documented cases of Northeast tornadoes. Mesoscale inhomogeneities due to terrain and baroclinic boundaries played a key role in the evolution and severity of the storm. The storm initiated at the intersection of an outflow boundary and a north–south-oriented baroclinic boundary. The mesocyclone was able to sustain itself as a result of sufficiently large amounts of low-level streamwise vorticity near the boundary despite subcritical values of 0–6-km vertical wind shear. Differential heating across the north–south-oriented boundary strengthened the pressure gradient across it. Strengthening ageostrophic flow across the boundary induced greater upslope flow along the southeastern slope of the Adirondack Mountains and induced terrain channeling up the Mohawk River valley. The channeling led to a maximum in moisture flux convergence and instability in the Mohawk valley. As the supercell moved into the Mohawk valley, radar and lightning data indicated a rapid intensification of the storm. Cold temperatures aloft due to the presence of an elevated mixed layer (EML) coincided with the surface instability to yield a local environment in the Mohawk valley favorable for extremely large hail. As the storm crossed the boundary, large values of 0–1-km wind shear, streamwise vorticity, and low lifting condensation levels combined to create a local environment favorable for tornadogenesis.
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Egholm, D. L., J. L. Andersen, M. F. Knudsen, J. D. Jansen, and S. B. Nielsen. "The periglacial engine of mountain erosion – Part 2: Modelling large-scale landscape evolution." Earth Surface Dynamics 3, no. 4 (October 6, 2015): 463–82. http://dx.doi.org/10.5194/esurf-3-463-2015.
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Abstract. There is growing recognition of strong periglacial control on bedrock erosion in mountain landscapes, including the shaping of low-relief surfaces at high elevations (summit flats). But, as yet, the hypothesis that frost action was crucial to the assumed Late Cenozoic rise in erosion rates remains compelling and untested. Here we present a landscape evolution model incorporating two key periglacial processes – regolith production via frost cracking and sediment transport via frost creep – which together are harnessed to variations in temperature and the evolving thickness of sediment cover. Our computational experiments time-integrate the contribution of frost action to shaping mountain topography over million-year timescales, with the primary and highly reproducible outcome being the development of flattish or gently convex summit flats. A simple scaling of temperature to marine δ18O records spanning the past 14 Myr indicates that the highest summit flats in mid- to high-latitude mountains may have formed via frost action prior to the Quaternary. We suggest that deep cooling in the Quaternary accelerated mechanical weathering globally by significantly expanding the area subject to frost. Further, the inclusion of subglacial erosion alongside periglacial processes in our computational experiments points to alpine glaciers increasing the long-term efficiency of frost-driven erosion by steepening hillslopes.
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Renner, Matthew A. M., Russell L. Barrett, Steve Clarke, James A. R. Clugston, Trevor C. Wilson, and Peter H. Weston. "Morphological and molecular evidence refute a broad circumscription for." Australian Systematic Botany 35, no. 3 (July 14, 2022): 127–79. http://dx.doi.org/10.1071/sb21030.
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Morphological and single-nucleotide polymorphism data support splitting Pultenaea glabra Benth. into eight species, including one in Victoria, and seven in eastern and northern New South Wales. Six species are newly described, five of which are, like P. glabra, narrow-range endemics within the Greater Blue Mountains World Heritage Area and adjacent sandstone landforms of the Great Dividing Range. The recognition of six new species from what was broadly P. glabra has implications for conservation management, including for P. glabra itself, which has a smaller distribution and more precise habitat requirements than previously thought. One of the new species, P. percussa, is known by a single 1971 gathering only. The occurrence of several narrow-range Blue Mountains endemic Pultenaea species may be explained by the combination of edaphic diversity and topographic complexity, which could act in concert to promote divergences among small, allopatric populations. Hybrids between P. glabra and P. flexilis Sm. are documented for the first time; however, limited evidence for introgression between the two species was observed. The following new taxa are described: Pultenaea aculeata M.A.M.Renner, P.H.Weston & S.Clarke, Pultenaea percussa M.A.M.Renner & P.H.Weston, Pultenaea furcata M.A.M.Renner & R.L.Barrett, Pultenaea mutabilis M.A.M.Renner & P.H.Weston, Pultenaea mutabilis var. angusta M.A.M.Renner, P.H.Weston, & S.Clarke, Pultenaea praecipua M.A.M.Renner & P.H.Weston, Pultenaea praecipua subsp. temperata M.A.M.Renner & R.L.Barrett, and Pultenaea tenebrosa M.A.M.Renner, P.H.Weston & S.Clarke. Lectotypes are designated for Pultenaea villosa var. glabrescens Benth. and Pultenaea weindorferi Reader.