Log in

Relevant bibliographies by topics / Geophysics Observations / Journal articles

Journal articles on the topic 'Geophysics Observations'

To see the other types of publications on this topic, follow the link: Geophysics Observations.

Author: Grafiati

Published: 10 December 2022

Last updated: 29 January 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Geophysics Observations.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Doyle, H. "Geophysics in Australia." Earth Sciences History 6, no. 2 (January 1, 1987): 178–204. http://dx.doi.org/10.17704/eshi.6.2.386k258604262836.

Full text

Abstract:

Geophysical observations began in Australia with the arrival of the first European explorers in the late 18th Century and there have been strong connections with European and North American geophysics ever since, both in academic and exploration geophysics. Government institutions, particularly the Bureau of Mineral Resources, have played a large part in the development of the subject in Australia, certainly more so than in North America. Academic research in geophysics has been dominated by that at the Australian National University. Palaeomagnetic research at the Australian National University has been particularly valuable, showing the large northerly drift of the continent in Cainozoic times as part of the Australia-India plate. Heat flow, electrical conductivity and upper mantle seismic velocities have been shown to be significantly different between Phanerozoic eastern Australia and the Western Shield. Geophysical exploration for metals and hydrocarbons began in the 1920s but did not develop strongly until the 1950s and 1960s. There are relatively few Australian geophysical companies and contracting companies, and instrumentation from North America and Europe have played an important role in exploration. Exploration for metals has been hampered by the deep weathered mantle over much of the continent, but the development of pulsed (transient) electromagnetic methods, including an Australian instrument (SIROTEM), has improved the situation. Geophysics has been important in several discoveries of ore-bodies. In hydrocarbon exploration the introduction of common depth point stacking and digital recording and processing in reflection surveys have played an important part in the discovery of offshore and onshore fields, as in other countries.

APA, Harvard, Vancouver, ISO, and other styles

2

Pollitz, F. F. "GEOPHYSICS: A New Class of Earthquake Observations." Science 313, no. 5787 (August 4, 2006): 619–20. http://dx.doi.org/10.1126/science.1131208.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Loginov, D. S. "Cartographic support of geophysical research: current situation and prospects." Geodesy and Cartography 950, no. 8 (September 20, 2019): 32–44. http://dx.doi.org/10.22389/0016-7126-2019-950-8-32-44.

Full text

Abstract:

The features of cartographic supporting geophysical research at the present stage of cartography and exploration geophysics development are discussed. The current situation and prospects of using GIS and web technologies are characterized basing on the analysis of scientific and industrial experience of domestic and foreign public as well as private geological and geophysical organizations. The analysis was performed at key stages of geophysical research, including the analysis of geological and geophysical studying the work area, designing geophysical works, field works, processing and interpretation of geophysical observations results, compilation of reporting materials, as well as the accumulation and storage of information. The examples of modern geoportals that provide quick access to geological and geophysical infor-mation in various forms of presentation, including cartographic data, are presented in article. The conclusions and recommendations were formulated according to results of the study. They are aimed at improving the efficiency of cartographic supporting geophysical research and the development of inter-sectoral interaction between cartography and geophysics.

APA, Harvard, Vancouver, ISO, and other styles

4

Ganiev, O. Z., T. A. Amashukeli, L. V. Farfuliak, and K. V. Petrenko. "Organization of the stationary seismological observations point." Geofizicheskiy Zhurnal 43, no. 5 (November 24, 2021): 232–40. http://dx.doi.org/10.24028/gzh.v43i5.244085.

Full text

Abstract:

The Institute of Geophysics of the NASU organizes and carries out continuous regional and local seismic observations on the territory of Ukraine. The article presents a universal modern model of seismic activity monitoring process, which is used in most international seismological agencies (USGS, EMSC, NEIC) and describes a typical stationary point of seismological observations of the National Seismological Network of the Institute of Geophysics of NAS of Ukraine. Seismological network of observations is a complex of systems consisting of stationary seismological points of registration of seismic waves, the distributed system of transfer and collecting of the seismological information, and also the center of operative processing of the data arriving from data registration points. The process of conducting regime seismological observations of local and remote seismic events on the territory of Ukraine and adjacent regions is described. Some important aspects of the need for comprehensive processing of registered events to identify local earthquakes and assess the current activity of tectonic structures in Ukraine are presented. The seismological network of the National Seismological Center of the Institute of Geophysics of the National Academy of Sciences of Ukraine is represented by a small number of stationary observation points: «Kiev-IRIS», «MI02-Poltava», «MI03-Skvyra», «MI04-Dnipro», «MI05-Stepanivka», «MI07-Mykolaiv», «ODS-Odesa», «MIU-Kryvyi Rih», and «MI06-Kremenchug». This number of seismological observation points does not actually provide seismic observation data to the central, eastern and southern parts of the territory of Ukraine and does not allow to reliably determine the level and quantitative characteristics of its seismic hazard. The seismic recorder Guralp CMG-40T manufactured by the British company GURALP SYSTEMS LIMITED is offered as optimal for the conditions and financial realities of Ukraine when organizing a stationary seismic observation point. It is proposed to use the seismological processing package SeisComP, which works on the SeedLink protocol, which is the basis of the data collection system by the Internet. This software product is the de facto world standard in the field of seismological data processing.

APA, Harvard, Vancouver, ISO, and other styles

5

Zhang, Jie. "President's Page: Looking into the world of medical imaging from the perspective of a geophysicist." Leading Edge 41, no. 6 (June 2022): 372–73. http://dx.doi.org/10.1190/tle41060372.1.

Full text

Abstract:

I have worked in the geophysical industry and in academia as a geophysicist for 25 years. During the same time frame, I have also worked for 24 years in the medical industry. I founded a geophysical imaging company in 1998, and a year later I cofounded a medical imaging company. During the last seven years, I have led two biomedical companies to develop treatment solutions for bacterial infections and cancers. My career path offers me a unique insight into the world of medical imaging from the perspective of a geophysicist. In the following, I would like to share some of my observations, based on that unique perspective.

APA, Harvard, Vancouver, ISO, and other styles

6

Bell, Ernest, Nicholas Schmerr, Ryan Porter, Jacob Bleacher, Kelsey Young, Mong-Han Huang, Vedran Lekic, and Donald Pettit. "Active seismic exploration along a human lunar mission traverse analogue in the San Francisco volcanic field." Leading Edge 41, no. 10 (October 2022): 690–99. http://dx.doi.org/10.1190/tle41100690.1.

Full text

Abstract:

Lunar surface activities during Apollo and terrestrial analogue lunar mission simulations have commonly focused on traverses that prioritize surface observations and sample collection activities. Along the way, geophysical measurements are often made. However, they are not necessarily made in a way that optimizes information about the physical subsurface properties, which is something that geophysics can provide. In 2010, NASA simulated a high-quality multiweek human lunar rover traverse analogue mission in the San Francisco volcanic field in Arizona. The traverse route and associated science station locations were selected based on addressing surface observation and sampling tasks. Geophysical studies were not included in the simulation. We returned to the same field area and obtained data on 19 active seismic refraction geophone lines from the science station locations accessed during the simulation. We analyzed the data to calculate 1D seismic velocity profiles for each of the lines. Results revealed up to seven distinct seismically defined material types, including a nearly ubiquitous veneer of regolith of variable thickness at the surface. Results also provided depth and thickness of the seven material types in the first 60 m of the subsurface at each of the science station locations. These cannot be obtained by geologic observations of the outcrops. Systematic interpretation of the area's overall subsurface stratigraphy was not feasible due to the geophysically nonsystematic nature of the original traverse's prioritization of the science station locations. The added geophysical understanding of a region could drive additional geologic investigations to locate samples of otherwise unknown material through the location of surface exposures or coring. This emphasizes the importance of synchronizing geologic and geophysical research requirements during lunar traverse planning and execution to optimize addressing scientific and utilization questions.

APA, Harvard, Vancouver, ISO, and other styles

7

Ozcep, F., and T. Ozcep. "Notes on the history of geophysics in the Ottoman Empire." History of Geo- and Space Sciences 5, no. 2 (September 5, 2014): 163–74. http://dx.doi.org/10.5194/hgss-5-163-2014.

Full text

Abstract:

Abstract. In Anatolia, the history of geophysical sciences may go back to antiquity (600 BC), namely the period when Thales lived in Magnesia (Asia Minor). In the modern sense, geophysics started with geomagnetic works in the 1600s. The period between 1600 and 1800 includes the measurement of magnetic declination, inclination and magnetic field strength. Before these years, there is a little information, such as how to use a compass, in the Kitab-i Bahriye (the Book of Navigation) of Piri Reis, who is one of the most important mariners of the Ottoman Empire. However, this may not mean that magnetic declination was generally understood. The first scientific book relating to geophysics is the book Fuyuzat-i Miknatissiye that was translated by Ibrahim Müteferrika and printed in 1731. The subject of this book is earth's magnetism. There is also information concerning geophysics in the book Cihannuma (Universal Geography) that was written by Katip Celebi and in the book Marifetname written by Ibrahim Hakki Erzurumlu, but these books are only partly geophysical books. In Istanbul the year 1868 is one of the most important for geophysical sciences because an observatory called Rasathane-i Amire was installed in the Pera region of this city. At this observatory the first systematic geophysical observations such as meteorological, seismological and even gravimetrical were made. There have been meteorological records in Anatolia since 1839. These are records of atmospheric temperature, pressure and humidity. In the Ottoman Empire, the science of geophysics is considered as one of the natural sciences along with astronomy, mineralogy, geology, etc., and these sciences are included as a part of physics and chemistry.

APA, Harvard, Vancouver, ISO, and other styles

8

GUPTA, M. DAS, SOMESHWAR DAS, K. PRASANTHI, P. K. PRADHAN, and U. C. MOHANTY. "Validation of upper-air observations taken during the ARMEX-I and its impact on the global analysis-forecast system." MAUSAM 56, no. 1 (January 19, 2022): 139–46. http://dx.doi.org/10.54302/mausam.v56i1.871.

Full text

Abstract:

During ARMEX-I several special observations were taken over Arabian Sea region and adjoining west coast of India, which gave an opportunity to study this region more thoroughly. To handle such voluminous data, ARMEX data center has been established at National Centre for Medium Range Weather Forecasting (NCMRWF), in collaboration with India Meteorological Department (IMD) and Indian Institute Technology (IIT), Delhi. One of the tasks of this center is to produce reanalysis for ARMEX period, utilizing these observations. It is essential to assimilate every observation from all available sources, especially over the data sparse oceanic regions for accurate determination of the three-dimensional structure of the atmospheric circulation. Before assimilating these data in global data assimilation system of NCMRWF, an attempt has been made to validate some of these data against observational facts from other sources. Upper-air observations (Digicora) from Dabolim, Goa have been compared with RS/RW observation of IMD, at Panjim, Goa. Though the trend in variations of all the meteorological parameters of these two stations is similar but there is a large difference in their absolute values. Reanalysis generated using the specially collected upper-air observations have been compared with the operational analysis of NCMRWF. The impact of these special observations on analysis and forecast system is found to be confined over the Arabian Sea region only in the lower troposphere. However, in the upper troposphere and stratosphere the impact is seen also over the equatorial Indian Ocean region.

APA, Harvard, Vancouver, ISO, and other styles

9

Carter, W. E., and D. S. Robertson. "Very-Long-Baseline Interferometry Applied to Geophysics." Symposium - International Astronomical Union 156 (1993): 133–44. http://dx.doi.org/10.1017/s0074180900173115.

Full text

Abstract:

Very-long-baseline Interferometry (VLBI) has opened for study a broad new spectrum of geophysical phenomena including: direct observation of the tectonic motions and deformations of the Earth's crustal plates, observations of unprecedented detail of the variations in the rotation of the Earth, and direct measurement of the elastic deformations of the Earth in response to tidal forces. These new measurements have placed significant constraints on models of the interior structure of the Earth; for example, measurements of the variations in the Earth's nutation have been shown to be particularly sensitive to the shape of the core-mantle boundary. The VLBI measurements will allow us to construct a global reference frame accurate at the centimeter level. Such a frame will be essential to studying long-term global changes, especially those changes related to sea-level variations as recorded by tide gauge measurements.

APA, Harvard, Vancouver, ISO, and other styles

10

Meyers, Patrick, Daniel C. Bowden, Tanner Prestegard, Victor C. Tsai, Vuk Mandic, Gary Pavlis, and Ross Caton. "Direct Observations of Surface‐Wave Eigenfunctions at the Homestake 3D Array." Bulletin of the Seismological Society of America 109, no. 4 (June 25, 2019): 1194–202. http://dx.doi.org/10.1785/0120190026.

Full text

Abstract:

Abstract Despite the theory for both Rayleigh and Love waves being well accepted and the theoretical predictions accurately matching observations, the direct observation of their quantifiable decay with depth has never been measured in the Earth’s crust. In this work, we present observations of the quantifiable decay with depth of surface‐wave eigenfunctions. This is done by making direct observations of both Rayleigh‐wave and Love‐wave eigenfunction amplitudes over a range of depths using data collected at the 3D Homestake array for a suite of nearby mine blasts. Observations of amplitudes over a range of frequencies from 0.4 to 1.2 Hz are consistent with theoretical eigenfunction predictions. They show a clear exponential decay of amplitudes with increasing depth and a reversal in sign of the radial‐component Rayleigh‐wave eigenfunction at large depths, as predicted for fundamental‐mode Rayleigh waves. Minor discrepancies between the observed eigenfunctions and those predicted using estimates of the local velocity structure suggest that the observed eigenfunctions could be used to improve the velocity model. Our results confirm that both Rayleigh and Love waves have the depth dependence that they have long been assumed to have. This is an important direct validation of a classic theoretical result in geophysics and provides new observational evidence that classical seismological surface‐wave theory can be used to accurately infer properties of Earth structure and earthquake sources.

APA, Harvard, Vancouver, ISO, and other styles

11

Matson, Dennis L., Torrence V. Johnson, Diana L. Blaney, and Glenn J. Veeder. "Ground-based observations of Io." Reviews of Geophysics 33 (1995): 505. http://dx.doi.org/10.1029/95rg00352.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Seino, Naoko, Tatsumi Nakano, Yoshiyuki Noto, and Kyoji Oono. "Validation of aerological observation simulation program and application to radiosonde observations in TOMACS." Papers in Meteorology and Geophysics 65 (2014): 1–14. http://dx.doi.org/10.2467/mripapers.65.1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Hadipandoyo, Sasongko. "Two Dimensional Interpolation of Potential Geophysics Data." Scientific Contributions Oil and Gas 15, no. 1 (April 6, 2022): 2–11. http://dx.doi.org/10.29017/scog.15.1.886.

Full text

Abstract:

Many types of geophysical survey involve making numerical observations as a large number of localities in a so called survey area. In order to display the result of such a survey in a way which can be easily assimilated by the interpreter they must be process a map form with the X and Y values (geographical position) associated with each data point.

APA, Harvard, Vancouver, ISO, and other styles

14

Abdelaziz, A. M., Makram Ibrahim, Zhipeng Liang, Xue Dong, and S. K. Tealib. "Orbit Predictions for Space Object Tracked by Ground-Based Optical and SLR Stations." Remote Sensing 14, no. 18 (September 9, 2022): 4493. http://dx.doi.org/10.3390/rs14184493.

Full text

Abstract:

In many cases, we have few optical observations over a short time span, and most of the information generated is too limited to compute a full orbit according to the angles-only method. This study aims to develop a mathematical model to determine the precise orbit from the optical observation data by the least squares method. We have used a set of the Global Navigational Satellite Systems, which are tracked by the Optical Satellite Tracking Station (OSTS) at the National Research Institute of Astronomy and Geophysics (NRIAG), Egypt, to access high-quality predictions for the orbits. We analyzed the orbit predictions from the observations of these satellites that are tracked from seven world stations using the laser ranging method, and the obtained results are compared with orbital elements produced using the Two-Line Element (TLE). The results showed that the orbital prediction accuracy differs for optical observations from laser observations because of the inaccuracy of the NORAD catalog information used; this is due to the difference between the time of observation and the epoch time of TLE.

APA, Harvard, Vancouver, ISO, and other styles

15

Marshall, John, and Friedrich Schott. "Open-ocean convection: Observations, theory, and models." Reviews of Geophysics 37, no. 1 (February 1999): 1–64. http://dx.doi.org/10.1029/98rg02739.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Ramaswamy, V., M. L. Chanin, J. Angell, J. Barnett, D. Gaffen, M. Gelman, P. Keckhut, et al. "Stratospheric temperature trends: Observations and model simulations." Reviews of Geophysics 39, no. 1 (February 2001): 71–122. http://dx.doi.org/10.1029/1999rg000065.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

MORGAN, Jason PHIPPS. "Mid‐Ocean Ridge Dynamics: Observations and Theory." Reviews of Geophysics 29, S2 (January 1991): 807–22. http://dx.doi.org/10.1002/rog.1991.29.s2.807.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

NOVÁK, Adam, and Juraj JANÁK. "Estimating the thermal effect in gPhoneX observations." Contributions to Geophysics and Geodesy 52, no. 4 (December 12, 2022): 501–15. http://dx.doi.org/10.31577/congeo.2022.52.4.1.

Full text

Abstract:

Stationary relative gravimeters are used in variety of applications, mainly due to their high sampling rate which is more suitable for study of certain geodynamic effects than absolute gravimeters. Study of weak signals is almost exclusively in the domain of superconducting gravimeters, as they possess the highest accuracy and stability of all types of relative gravimeters. Possible alternative to superconducting gravimeters are portable earth tide metal spring gravimeters. Zero-length spring gravimeters (e.g. LCR instruments) are usually considered to be the most accurate mechanical spring gravimeters. However, compared to superconducting instruments they remain too unstable for long-term gravity monitoring. Main reason supporting this statement is related to instrument's sensitivity to temperature changes and temperature induced tilts. Gravity observations from the gPhoneX #108 gravimeter stationed at Hurbanovo gravimetric observatory were tested in order to confirm the correlation between the observed gravity changes and ambient temperature changes and provide a solution for correcting the gPhone data for influence of the ambient temperature changes. Paper also aims to serve as a guide for other operators to estimate a parameters required for the calculation of ambient temperature correction.

APA, Harvard, Vancouver, ISO, and other styles

19

KOPPAR, A. L. "CLOUD OBSERVATIONS AT ANTARCTICA." MAUSAM 42, no. 3 (February 28, 2022): 307–8. http://dx.doi.org/10.54302/mausam.v42i3.3245.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Maksymchuk, V., І. Chobotok, R. Kuderavets, Ye Nakalov, N. Pyrizhok, O. Pavlyuk, and L. Yanush. "Results of long-term tectonomagnetic research in the Akademik Vernadsky station region, the West Coast of the Antarctic Peninsula." Ukrainian Antarctic Journal 20, no. 1(24) (2022): 3–17. http://dx.doi.org/10.33275/1727-7485.1.2022.685.

Full text

Abstract:

The study aims to analyze the results of long-term tectonomagnetic observations on the Antarctic tectonomagnetic polygon in the region of the Akademik Vernadsky station to investigate the current geodynamics at the West Coast of the Antarctic Peninsula. The data (1998—2020) were collected as regular discrete geomagnetic measurements. They were used to study the temporal changes of the local magnetic field between the observation epochs and tectonomagnetic anomalies. We create a temporal series of the changes in the local magnetic field for every point of the observation network on the polygon and provide the map of tectonomagnetic anomalies over different observation periods. The tectonomagnetic anomalies of 2.0—2.8 nT · year–1 were found in the Argentine Islands region. The anomalies’ spatial structure agrees with elements of the tectonic structure of the Earth crust. We studied the spatial-temporal connection of the tectonomagnetic anomalies with the region seismicity and estimated the values of tectonic stresses in the lithosphere within the piezomagnetic mechanism. The spatial-temporal structure of tectonomagnetic anomalies in the region shows the response of the geological environment to the change in the tectonic stresses in the local crust. Based on the theoretical calculations and other geological and geophysical data, we conclude that a piezomagnetic effect causes the anomalies under the action of stretching tectonic stresses (~1 bar · year–1) in the sub-latitudinal direction. Given the urgency of discovering the seismotectonic processes and current regional dynamics, the tectonomagnetic observations on the polygon should be continued as a yearly monitoring program, including other methods of geophysics and geodesy.

APA, Harvard, Vancouver, ISO, and other styles

21

JOSEPH, K. JOSSIA, M. HARIKRISHNAN, G. RAJESH, and K. PREMKUMAR. "Moored buoy observations in Arabian Sea warm pool." MAUSAM 56, no. 1 (January 19, 2022): 161–68. http://dx.doi.org/10.54302/mausam.v56i1.890.

Full text

Abstract:

Time series observations from four moored data buoys in the south eastern Arabian Sea for a period of four months (March - June 2003) are utilized to study the characteristics of warm pool. The moored buoy observations show fair weather conditions in the pre-monsoon period with weak variable winds and calm sea conditions. High SST has been observed during the pre-monsoon warming phase. Surface met observation shows comparatively low-pressure in the region for a period of two weeks starting from the last week of April 2003. Increased wind speed and wave height with a clockwise rotation in wind direction and occasional rains are reported during that period. An interesting observation is the cooling of SST in response to the May 2003 cyclone in Bay of Bengal. Another feature during the warming phase is an oscillation of the order of 14 days observed in SST. Time series observations of salinity in the month of March show the presence of low saline water in the warm pool. A sudden drop of 0.4 psu in surface salinity was observed on 2nd April, which may be due to the advection of low saline plumes in the warm pool region and/or the local pre-monsoon showers. The onset of southwest monsoon and the associated monsoon currents dissipated the warm pool and thereafter the monsoon conditions with high winds, rough sea and frequent rains prevailed in the region.

APA, Harvard, Vancouver, ISO, and other styles

22

Zheng, Y. "Effect of earthquakes on observations of time and latitude." Symposium - International Astronomical Union 128 (1988): 405–10. http://dx.doi.org/10.1017/s0074180900119801.

Full text

Abstract:

According to a vast amount of both seismological and astronomical data obtained from China, it has been understood that: 1, A large number of anomalies may appear before and after the major earthquake and the anomalous area is usually very large; 2, And therefore the anomalous residuals in the observations of time and latitude before the shock are of profound significance in geophysics.

APA, Harvard, Vancouver, ISO, and other styles

23

RAGHAVAN, S. "Radar observations of tropical cyclones over the Indian Seas." MAUSAM 48, no. 2 (December 15, 2021): 169–88. http://dx.doi.org/10.54302/mausam.v48i2.3962.

Full text

Abstract:

ABSTRACT. A review is presented of the radar observation of tropical cyclones in the Indian seas. The use of radar in operational cyclone tracking and forecasting as well as the knowledge gained from radar observations of the structure, wind and rainfall distribution and motion of cyclones are discussed. In the context of the expected introduction of operational Doppler ra1ars in India, the future prospects in the use of radar for operations and research are outlined. Some important areas where our understanding of cyclones can be improved by studies with radar in conjunction with other observations are listed.

APA, Harvard, Vancouver, ISO, and other styles

24

Seleznev, V. S., A. V. Liseikin, A. A. Emanov, and A. Yu Belinskaya. "Geophysical observations during the flight of the Chelyabinsk meteoroid." Russian Geology and Geophysics 55, no. 3 (March 2014): 405–10. http://dx.doi.org/10.1016/j.rgg.2014.01.022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Imrišek, Martin, Mária Derková, and Juraj Janák. "Estimation of GNSS tropospheric products and their meteorological exploitation in Slovakia." Contributions to Geophysics and Geodesy 50, no. 1 (May 24, 2020): 83–111. http://dx.doi.org/10.31577/congeo.2020.50.1.5.

Full text

Abstract:

This paper discusses the in near–real time processing of Global Navigation Satellite System observations at the Department of Theoretical Geodesy at the Slovak University of Technology in Bratislava. Hourly observations from Central Europe are processed with 30 minutes delay to provide tropospheric products. The time series and maps of tropospheric products over Slovakia are published online. Zenith total delay is the most important tropospheric parameter. Its comparison with zenith total delays from IGS and E–GVAP solutions and the validation of estimated zenith total delay error over year 2018 have been made. Zenith total delays are used to improve initial conditions of numerical weather prediction model by the means of the three–dimensional variational analysis at Slovak Hydrometeorological Institute. The impact of assimilation of different observation types into numerical weather prediction model is discussed. The case study was performed to illustrate the impact of zenith total delay assimilation on the precipitation forecast.

APA, Harvard, Vancouver, ISO, and other styles

26

de Groot-Hedlin, Catherine D. "Seismic T-Wave Observations at Dense Seismic Networks." Seismological Research Letters 91, no. 6 (August 19, 2020): 3444–53. http://dx.doi.org/10.1785/0220200208.

Full text

Abstract:

Abstract Seismic T waves, which result from transformation of hydroacoustic to seismic energy at coastlines, were investigated for two strong earthquakes. A 2014 Caribbean event generated seismic T waves that were detected at over 250 seismometers along the east coast of the U.S., primarily at seismic stations operated by the USArray Transportable Array. A 2006 Hawaiian event generated seismic T waves observed at over 100 seismometers along the west coast. Seismic T-wave propagation was treated as locally 2D where the incoming hydroacoustic wavefronts were nearly parallel to the coastlines. Along the east coast, seismic T-wave propagation velocities were consistent with surface waves and a polarization analysis indicated that they were transverse waves, supporting their interpretation as Love waves. They were observed at inland distances up to 1134 km from the east coast. Along the west coast, the propagation velocity was over 5 km/s and a polarization analysis confirmed that the seismic T waves propagated as seismic P waves. Differences between the modes of propagation along the east and west coasts are attributed to differences in the slope and thickness of the sediment coverage at the continental slopes where hydroacoustic to seismic conversion takes place.

APA, Harvard, Vancouver, ISO, and other styles

27

Zuccarello, Francesca, Lidia Contarino, Paolo Romano, Viviana Battiato, and Salvo L. Guglielmino. "Multi-wavelength observations of flares and eruptive filaments." Acta Geophysica 57, no. 1 (July 25, 2008): 24–30. http://dx.doi.org/10.2478/s11600-008-0040-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Kozak, P., and L. Kozak. "On the possibility of using thermal vision cameras for observations of meteors and other atmospheric formations in long wave infrared." Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, no. 60 (2019): 33–38. http://dx.doi.org/10.17721/btsnua.2019.60.33-38.

Full text

Abstract:

The characteristics of the modern low-cost thermal vision cameras for possible observations of meteors and other atmospheric formations in long wave infrared spectrum range of 8-14 μm are investigated. An overview of meteor observations in non-traditional spectrum ranges: ultra-violet, near infrared, short wave, mid wave, and long wave infrared is done. A short description of the modern instruments for infrared observations is presented. By the example of a modern inexpensive model of thermal vision camera of the lower price segment there are presented results of test observations of clouds, possible atmospheric bolide tails and inversion t tracks of airplanes, meteors, and thunderstorm discharges. A short analysis of technical characteristics of the selected model, and corresponding software is given, the merits and demerits of the given type of observational instruments are analyzed as well. The conclusion for outlook of using in the future the thermal vision cameras in meteor astronomy and geophysics is done.

APA, Harvard, Vancouver, ISO, and other styles

29

MITRA, H. "Radar observations of a thunderstorm." MAUSAM 6, no. 2 (December 3, 2021): 119–36. http://dx.doi.org/10.54302/mausam.v6i2.4430.

Full text

Abstract:

The paper describes the results of a study of a winter thunderstorm which occurred at New Delhi between 2150 IST of the 14th and 0030 1ST of 15 January 1953 due to the passage of a western disturbance. The radar echoes as seen on the scope of a 3-cm'AN/APQ-13 set have been explained with the help of the available surface and upper air data. The mechanism of formation and decay of the main thunder storm cell and its associated secondaries have been described with the help of radar photographs taken at short intervals.

APA, Harvard, Vancouver, ISO, and other styles

30

NAIDU, J. V. M. "SEA BREEZE OBSERVATIONS AT BHUBANESWAR." MAUSAM 42, no. 4 (February 28, 2022): 411–12. http://dx.doi.org/10.54302/mausam.v42i4.3280.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Podestá, Luis, Esteban Sáez, Gonzalo Yáñez, and Felipe Leyton. "Geophysical Study and 3-D Modeling of Site Effects in Viña del Mar, Chile." Earthquake Spectra 35, no. 3 (August 2019): 1329–49. http://dx.doi.org/10.1193/080717eqs155m.

Full text

Abstract:

The Maule 2010 earthquake (Mw 8.8) produced damage to several buildings throughout Central Chile. This was particularly the case in downtown Viña del Mar, where an anomalous concentration of structural damage was found in several medium-rise buildings distributed along a narrow area approximately 1 km in length. These observations suggest the possibility of a localized area of seismic amplification effects. We conducted a geophysical characterization using surface wave–based techniques and gravimetry to characterize the main dynamic properties of the soil and the depth of the basin. These data, complemented with several standard penetration test measurements, were used to develop a three-dimensional (3-D) geotechnical characterization of the area. Additionally, the cyclic behavior of predominant materials was experimentally characterized based on remolded samples. To assess complex site-amplification effects, we developed a computational 3-D model constrained by surface-wave geophysics and laboratory results, assuming a homogenous basin infill with increasing stiffness with depth. The results partially agree with damage observations and suggest an explanation related to basement shape in some areas of the modeled region.

APA, Harvard, Vancouver, ISO, and other styles

32

Smalls, Paris T., Robert A. Sohn, and John A. Collins. "Lake‐Bottom Seismograph Observations of Microseisms in Yellowstone Lake." Seismological Research Letters 90, no. 3 (April 3, 2019): 1200–1208. http://dx.doi.org/10.1785/0220180242.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Hofstetter, Rami, Peter Malin, and Zvi Ben-Avraham. "Seismic Observations of Microearthquakes from the Masada Deep Borehole." Seismological Research Letters 91, no. 4 (May 6, 2020): 2298–309. http://dx.doi.org/10.1785/0220190391.

Full text

Abstract:

Abstract A better understanding of the Dead Sea basin (DSB) tectonics and hazards can be achieved through high-sensitivity observations of its seismic activity. Accordingly, we have taken advantage of the Masada deep borehole (MDBI), an abandoned oil well on the western shore of the Dead Sea rift, to install a seismometer at 1516 m below sea level—a 2 Hz three-component seismometer. The MDBI station is near the east Masada fault, part of the western boundary fault of the DSB. Seismological measurements conducted at these depths can provide more information than possible with surface observations—in this case, recording 1491 high-quality seismograms as compared to 103 by the local national network. The MDBI seismograms also have significantly higher signal-to-noise ratio than the on-surface observations of nearby Israel Seismic Network (ISN) stations. This lowers the detection threshold down to well below M = 0 on the ISN scale. Many of these earthquakes, sometimes occurring in clusters, take place almost under MDBI, at depths of 10–25 km. Using cross-correlation techniques, we found several sequences of earthquake clusters underneath both the station and along the Dead Sea fault (DSF). The b-value obtained by the frequency–magnitude relationship of these events is somewhat higher than the value for the DSF area taken as a whole.

APA, Harvard, Vancouver, ISO, and other styles

34

Momani, Mohammad Awad, Mohd Alauddin Mohd Ali, Baharudin Yatim, Mardina Abdullah, and Norbahia Misran. "GPS observations at quasi-conjugate points under disturbed conditions." Acta Geophysica 56, no. 4 (August 11, 2008): 1179–201. http://dx.doi.org/10.2478/s11600-008-0048-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Cho, John Y. N., and Michael C. Kelley. "Polar mesosphere summer radar echoes: Observations and current theories." Reviews of Geophysics 31, no. 3 (1993): 243. http://dx.doi.org/10.1029/93rg01535.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Barry, R. G., M. C. Serreze, J. A. Maslanik, and R. H. Preller. "The Arctic Sea Ice-Climate System: Observations and modeling." Reviews of Geophysics 31, no. 4 (1993): 397. http://dx.doi.org/10.1029/93rg01998.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Gurnett, D. A., and U. S. Inan. "Plasma wave observations with the Dynamics Explorer 1 spacecraft." Reviews of Geophysics 26, no. 2 (1988): 285. http://dx.doi.org/10.1029/rg026i002p00285.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Li, Yaoguo, Aline Melo, Cericia Martinez, and Jiajia Sun. "Geology differentiation: A new frontier in quantitative geophysical interpretation in mineral exploration." Leading Edge 38, no. 1 (January 2019): 60–66. http://dx.doi.org/10.1190/tle38010060.1.

Full text

Abstract:

Geophysics aims to image subsurface geologic structure and identify different geologic units. While the former has dominated the interpretation of applied geophysical data, the latter has received much less attention. This appears to have persisted despite applications such as those in mineral exploration that inherently rely on the inference of geologic units from geophysical and geologic observations. In practice, such activities are routinely carried out in a qualitative manner. Thus, it is meaningful to examine this aspect and to develop a system of quantitative approaches to identify different geologic units. The development of geophysical inversions in the last three decades makes such interpretation tools possible. We refer to this newly emerging direction as geology differentiation and the resultant representation of geology model as a quasi-geology model. In this article, we will provide an overview of the historical background of geology differentiation and the current developments based on physical property inversions of geophysical data sets. We argue that integrating multiple physical property models to differentiate and characterize geologic units and work with the derived quasi-geology model may lead to a step change in maximizing the value of geophysical inversions.

APA, Harvard, Vancouver, ISO, and other styles

39

Richter, H., J. Makris, and R. Rihm. "Geophysical observations offshore Saudi Arabia: seismic and magnetic measurements." Tectonophysics 198, no. 2-4 (November 1991): 297–310. http://dx.doi.org/10.1016/0040-1951(91)90157-n.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Tulaczyk, Slawek, Jill A. Mikucki, Matthew R. Siegfried, John C. Priscu, C. Grace Barcheck, Lucas H. Beem, Alberto Behar, et al. "WISSARD at Subglacial Lake Whillans, West Antarctica: scientific operations and initial observations." Annals of Glaciology 55, no. 65 (2014): 51–58. http://dx.doi.org/10.3189/2014aog65a009.

Full text

Abstract:

AbstractA clean hot-water drill was used to gain access to Subglacial Lake Whillans (SLW) in late January 2013 as part of the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project. Over 3 days, we deployed an array of scientific tools through the SLW borehole: a downhole camera, a conductivity–temperature–depth (CTD) probe, a Niskin water sampler, an in situ filtration unit, three different sediment corers, a geothermal probe and a geophysical sensor string. Our observations confirm the existence of a subglacial water reservoir whose presence was previously inferred from satellite altimetry and surface geophysics. Subglacial water is about two orders of magnitude less saline than sea water (0.37–0.41 psu vs 35 psu) and two orders of magnitude more saline than pure drill meltwater (<0.002 psu). It reaches a minimum temperature of –0.55~C, consistent with depression of the freezing point by 7.019 MPa of water pressure. Subglacial water was turbid and remained turbid following filtration through 0.45 µm filters. The recovered sediment cores, which sampled down to 0.8 m below the lake bottom, contained a macroscopically structureless diamicton with shear strength between 2 and 6 kPa. Our main operational recommendation for future subglacial access through water-filled boreholes is to supply enough heat to the top of the borehole to keep it from freezing.

APA, Harvard, Vancouver, ISO, and other styles

41

Stöffler, Dieter, Natalia A. Artemieva, Kai Wünnemann, W. Uwe Reimold, Juliane Jacob, Birgit K. Hansen, and Iona A. T. Summerson. "Ries crater and suevite revisited-Observations and modeling Part I: Observations." Meteoritics & Planetary Science 48, no. 4 (April 2013): 515–89. http://dx.doi.org/10.1111/maps.12086.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Lindsey, Nathaniel J., T. Craig Dawe, and Jonathan B. Ajo-Franklin. "Illuminating seafloor faults and ocean dynamics with dark fiber distributed acoustic sensing." Science 366, no. 6469 (November 28, 2019): 1103–7. http://dx.doi.org/10.1126/science.aay5881.

Full text

Abstract:

Distributed fiber-optic sensing technology coupled to existing subsea cables (dark fiber) allows observation of ocean and solid earth phenomena. We used an optical fiber from the cable supporting the Monterey Accelerated Research System during a 4-day maintenance period with a distributed acoustic sensing (DAS) instrument operating onshore, creating a ~10,000-component, 20-kilometer-long seismic array. Recordings of a minor earthquake wavefield identified multiple submarine fault zones. Ambient noise was dominated by shoaling ocean surface waves but also contained observations of in situ secondary microseism generation, post–low-tide bores, storm-induced sediment transport, infragravity waves, and breaking internal waves. DAS amplitudes in the microseism band tracked sea-state dynamics during a storm cycle in the northern Pacific. These observations highlight this method’s potential for marine geophysics.

APA, Harvard, Vancouver, ISO, and other styles

43

Ihnatyshyn, V., D. Malytskyy, T. Izhak, M. Ihnatyshyn, and A. Ihnatyshyn. "MONITORING SEISMOTECTONIC PROCESSES IN THE TRANSCARPATHIAN INNER TROUGH BASED ON THE RESULTS OF COMPLEX GEOPHYSICAL OBSERVATIONS." Visnyk of Taras Shevchenko National University of Kyiv. Geology, no. 3(98) (2022): 42–48. http://dx.doi.org/10.17721/1728-2713.98.05.

Full text

Abstract:

The article is devoted to the study of relations between the parameter variations of geophysical fields and the geodynamic state of the Transcarpathian Inner Trough. The research aims at studying the relations between the geodynamic state, observed meteorological parameters, and seismic phenomena in the Transcarpathian Inner Trough. Exploration target: seismotectonic processes in the region based on the results of monitoring geophysical fields. The scope of research includes the spatiotemporal distribution of local seismicity, modern lateral movements of the Earth's crust in the Oaș deep-seated fault area, precipitation parameter variations, water level in the Tysa River in 2019–2020. Research methodology presupposes the use of dynamic characteristics of modern lateral movements of the Earth's crust, spatiotemporal distribution of local earthquakes, observation of precipitation, as well as the comparison of heavy precipitation intervals with periods of seismic intensification. The research uses data obtained in the course of monitoring geophysical observations in the Transcarpathian Inner Trough area, especially at monitoring geophysical stations of the Seismicity Department of the Carpathian region of S.I. Subbotin Institute of Geophysics of the National Academy of Sciences of Ukraine. The data on the movements of the Earth's crust have been obtained at "Korolevo" strainmeter station. The results are significant to study the possible occurrence of local seismicity in the region and to settle the issue of seismically hazardous territories, as well as prediction of seismically hazardous phenomena in the future. The research studies the relation between the dynamic characteristics of modern lateral movements of the Earth's crust in the central part of the Transcarpathian Inner Trough and local seismicity in periods of intensive precipitation. The authors studied the relations between precipitation parameter variations and spatiotemporal distribution of local seismicity in 2019–2020. The analysis of spatiotemporal distribution of local seismicity and precipitation parameter variations in 2020 testifies to a high correlation of geophysical data series: increased amounts of precipitation are accompanied by an increased number of registered local earthquakes in the region; the hydrological aspect of seismotectonic processes in the Transcarpathian Inner Trough has been substantiated. In 2020 rock compression could be observed in the Oaș deep-seated fault area.

APA, Harvard, Vancouver, ISO, and other styles

44

Quintero, Ronnie, and Ota Kulhanek. "Pn-wave observations in Costa Rica." Geofísica Internacional 37, no. 3 (July 1, 1998): 171–82. http://dx.doi.org/10.22201/igeof.00167169p.1998.37.3.391.

Full text

Abstract:

Tiempos de arribos, medidos en la Red Sismográfica de Costa Rica, fueron empleados para extraer información sobre la cortezay el manto por debajo de Costa Rica. Datos de tiempos de arribo de la onda P y S de 100 sismos locales y regionales ocurridosdurante el período 1984-1990 fueron usados para obtener la velocidad Pn, la razón de Poisson, la anisotropía de la velocidad Pn y lacorreción de las estaciones. La razón de Poisson para la capa superior del manto por debajo de Costa Rica es 0.265 y la velocidad dePn encontrada es de 7.81 km/sec. La presente investigación no muestra variaciones anisotrópicas significantes para la onda Pn. Laprofundidad del Moho se calcula en 34 km, aproximadamente.

APA, Harvard, Vancouver, ISO, and other styles

45

Bravo, S., and A. Hewish. "Geomagnetic storms forecast using IPS observations." Geofísica Internacional 27, no. 2 (April 1, 1988): 191–98. http://dx.doi.org/10.22201/igeof.00167169p.1988.27.2.782.

Full text

Abstract:

La observación del centelleo interplanetario (IPS) de radiofrecuencias estelares de diámetro pequeño permite la detección y el rastreo de perturbaciones en el viento solar que viajan desde los hoyos coronales en el Sol hacia la Tierra, causando a su llegada perturbaciones geomagnéticas e ionosféricas. Durante el periodo de julio de 1978 a septiembre de 1979, se llevo a cabo un monitoreo continuo del centelleo de 900 fuentes estelares de radio y se encontró que la mayoría de los comienzos repentinos (SC) de tormentas geomagnéticas ocurrieron más de un día después, y algunos hasta cuatro o cinco días después de que se detecto por primera vez la perturbación en el medio interplanetario a través del centelleo. Esto demuestra que un monitoreo permanente del dentelleo interplanetario de las radiofuentes proporciona una herramienta muy útil en el pronóstico de las perturbaciones geomagnéticas y los efectos asociados a ellas.

APA, Harvard, Vancouver, ISO, and other styles

46

IYER, N. V. "A NULL DETECTOR FOR PYRHELIOMETER OBSERVATIONS." MAUSAM 25, no. 3 (February 21, 2022): 503. http://dx.doi.org/10.54302/mausam.v25i3.5265.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Green, D. N., and D. Bowers. "Seismic Raves: Tremor Observations from an Electronic Dance Music Festival." Seismological Research Letters 79, no. 4 (July 1, 2008): 546–53. http://dx.doi.org/10.1785/gssrl.79.4.546.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Sargeant, S. L., P. J. Stafford, R. Lawley, G. Weatherill, A. J. S. Weston, J. J. Bommer, P. W. Burton, et al. "Observations from the Folkestone, U.K., Earthquake of 28 April 2007." Seismological Research Letters 79, no. 5 (September 1, 2008): 672–87. http://dx.doi.org/10.1785/gssrl.79.5.672.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

PARASKEVAS, Melissinos, Demitris PARADISSIS, Konstantinos RAPTAKIS, Paraskevi NOMIKOU, Emilie HOOFT, and Konstantina BEJELOU. "Gravity observations on Santorini island (Greece): Historical and recent campaigns." Contributions to Geophysics and Geodesy 51, no. 1 (March 15, 2021): 1–24. http://dx.doi.org/10.31577/congeo.2021.51.1.1.

Full text

Abstract:

Santorini is located in the central part of the Hellenic Volcanic Arc (South Aegean Sea) and is well known for the Late-Bronze-Age “Minoan” eruption that may have been responsible for the decline of the great Minoan civilization on the island of Crete. To use gravity to probe the internal structure of the volcano and to determine whether there are temporal variations in gravity due to near surface changes, we construct two gravity maps. Dionysos Satellite Observatory (DSO) of the National Technical University of Athens (NTUA) carried out terrestrial gravity measurements in December 2012 and in September 2014 at selected locations on Thera, Nea Kameni, Palea Kameni, Therasia, Aspronisi and Christiana islands. Absolute gravity values were calculated using raw gravity data at every station for all datasets. The results were compared with gravity measurements performed in July 1976 by DSO/NTUA and absolute gravity values derived from the Hellenic Military Geographical Service (HMGS) and other sources. Marine gravity data that were collected during the PROTEUS project in November and December 2015 fill between the land gravity datasets. An appropriate Digital Elevation Model (DEM) with topographic and bathymetric data was also produced. Finally, based on the two combined datasets (one for 2012–2014 and one for the 1970s), Free air and complete Bouguer gravity anomaly maps were produced following the appropriate data corrections and reductions. The pattern of complete Bouguer gravity anomaly maps was consistent with seismological results within the caldera. Finally from the comparison of the measurements made at the same place, we found that, within the caldera, the inner process of the volcano is ongoing both before, and after, the unrest period of 2011–2012.

APA, Harvard, Vancouver, ISO, and other styles

50

Barański, Piotr, and Paweł Bodzak. "Some observations of bipolar flashes during summer thunderstorms near Warsaw." Acta Geophysica 54, no. 1 (March 2006): 71–89. http://dx.doi.org/10.2478/s11600-006-0007-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!