Littérature scientifique sur le sujet « South-Eastern Alps »

WhileBufo bufois widespread in Europe, the closely relatedB. spinosusis parapatrically distributed in Western Europe and Northern Africa. The exact course of the contact zone between both taxa, however, is still unknown. 24 samples from Switzerland were analysed using mitochondrial and nuclear markers combined with 243 previously published samples from Europe and Asia. No haplotypes ofB. spinosuswere detected in Switzerland, only two mitochondrial haplotypes ofB. bufo: one north and south of the Alps, the other only north of the Alps. Both haplotypes are also widely distributed in Eastern and Central Europe. These results agree with a postglacial recolonisation of Central Europe from refugia on the Balkan Peninsula. The occurrence of one haplotype north and south of the Alps can be explained by colonisation either from the north by crossing the Alps or from the east along the southern edge of the Alps. The rapid postglacial recolonisation from Balkan refugia might have prevented the spread of southern haplotypes from Italy and ofB. spinosusfrom France.

The clastic sedimentary formations of the Saint Antonin basin in the French Maritime Alps contain the record of the Early Oligocene erosional history of the Maures-Esterel massif, Sardinia and Corsica. Detrital apatite fission-track dating and zircon fission-track/U-Pb double dating of samples collected from the Saint Antonin basin confirm sediment provenance and allow obtaining first-order estimates of drainage basin maximum and long-term average exhumation rates. Whereas average exhumation rates were on the order of 0.1–0.2 km/Myr during the Early Oligocene, small parts of the Saint Antonin basin source areas may have experienced maximum exhumation rates on the order of 0.4–0.7 km/Myr. Although zircons and apatites with Early Oligocene fission-track cooling ages make up between 11–15% of the dated grains, a possible volcanic contribution is negligible, as only one single volcanic zircon grain was identified by fission-track/U-Pb double dating. Regional geodynamic processes with convergence in the Western Alps to the east and the end of the Pyreneo-Provençal compression phase by the early Oligocene controlled the differences in basin fill history and sediment provenance between the Saint Antonin basin and the largely contemporaneous Barrême basin in south-eastern France.

Fibulae with a knob on a backward-bent foot, of which different variants of the Picugi type are probably best known, evolved in the eastern Adriatic and its hinterland, and the wider south-eastern Alps during the last two centuries BC. A similar but distinct type of fibula named the Rakitno type has been identified based on its morphological characteristics and distribution. Fibulae of this type have mainly been recorded at sites in Bosnia and Herzegovina, but also in the Sava valley and eastern Slavonia. Similarities in the way they are decorated, with a series of knobs on the backward-bent foot, link fibulae of the Rakitno type with other contemporary forms recorded in the south-eastern part of the Carpathian Basin (fibulae of the Jarak type) and the south-eastern Alps (fibulae of the Mihovo type), indicating that designs were exchanged and then adapted to different communities in local workshops. On the other hand, finds of fibulae of the Rakitno type at sites in eastern Slavonia attest to contacts with communities settled in the western Balkans. Despite the absence of finds from closed associations, documented comparisons allow for fibulae of the Rakitno type to be dated to the latter half of the 2nd and the early 1st centuries BC, with the assumption that this design was typical of female costume.

AbstractThe epiphytic lichenPorina pseudohibernicais described as new. It is characterized by a richly isidiate thallus, 7–8(–9)-septate ascospores and the presence of periphyses. It resemblesP. hibernicas. str., differing in the size and septation of ascospores, and in the dimensions of the terete, branched isidia. The new species was found fertile at a single site in the Carnic Alps (SE Alps, Italy), but it is also known in a sterile condition from scattered localities in the humid (sub-)montane belt of Slovenia, the Czech Republic and Ukraine, occurring on smooth bark ofFagusandCarpinus.Porina hibernicais restricted to the coastal lowlands of Atlantic Europe, and it prefers rather dry, base-rich bark ofQuercusandUlmus. The characters previously used to segregate the isidiate EuropeanPorinainto the genusZamenhofiaare also discussed.

AbstractResults of stratigraphic and morphotectonic analyses on fluvial terraces at the outlet of the Meduna valley in the eastern Southern Alps are used to investigate on the tectonics and paleoclimate. The Meduna valley, prone to destructive earthquakes, belongs to the front of the eastern Southern Alps, a south-verging fold and thrust belt in evolution from the Middle Miocene to the present, constructed by ENE–WSW striking, SSE-verging medium to low-angle thrusts, gradually propagating in the Venetian–Friulian plain. In the study area, located south of the Periadriatic thrust, the main structural element is the ENE–WSW striking Maniago–M. Jouf thrust system. Seven depositional units, ranging in age from Pliocene to Holocene, and a hierarchy of four numbered terrace complexes were identified. Stratigraphic and geometric relationships between sedimentary units, basal surfaces and terraces allow the reconstruction of the chronology of the depositional events. The study shows that the valley configuration has been shaped during the Pliocene–Quaternary with long-lasting steady intervals, interspaced with periodic tectonic pulses of the thrust front of the eastern Southern Alps. The most recent pulse related to the Maniago thrust shows an upper Pleistocene–Holocene slip rate of about 0.6 mm/yr.

In the last years extensive outbreaks of the pine engraver beetle Ips acuminatus (Gyllenhal) (Coleoptera: Curculionidae, Scolytinae) have been reported in many Scots pine (Pinus sylvestris) forests in the Alps including the valley of Boite (Dolomites). The beetle has been considered for a long time of minor economic importance, but recently it has been included among the ten most damaging wood boring insect in Europe as a result of the increasing tree mortality caused by this species. Extrinsic factors such as high temperature and drought are known to trigger outbreaks of I. acuminatus and it is likely that climate change may aggravate the threat to pine forests, either with the beetle alone or in combination with secondary pathogens and pests, as the recent infestations seem to confirm. I. acuminatus is one of the most common bark beetles infesting Scots pine (Pinus sylvestris) in Eurasia. It is a polygamous species with up to 6-12 females joining each male within the gallery systems. The maternal galleries radiate outward from the central nuptial chamber (formed by the male) creating a distinctive star-shaped pattern. Eggs are laid on both sides of the maternal galleries. Larval galleries develop shortly in the phloem as I. acuminatus is a phloemycetophagous species associated with Ophiostoma brunneo-ciliatum and Ambrosiella macrospora. Before emerging, callow adults need a period of maturation feeding that takes place in the phloem close to the galleries where the larvae have developed. The adults infest the upper part of the trunk and the branches, as a bark thickness of 2-3 mm is preferred. Literature reports I. acuminatus as monovoltine in Scandinavia and bivoltine in southern Europe, overwintering as adult mainly under the bark of the infested trees. However, overwintering in the litter has been considered possible in northern populations. Spring emergence begins slowly when air temperature reaches 14°-16°C, but the real mass flight occurs when temperature exceeds 18°C. As many other bark beetle species, I. acuminatus have a very pronounced spatial patterning linked to the cooperative attack strategy it adopts, resulting in a „spot infestation‟. This dissertation addresses poorly known aspects of the biology of the bark beetle observed during the outbreak that started in 2005 in the south-eastern Alps, with particular focus on: - voltinism, phenology and breeding performance in relation to both temperature and colonisation density, in order to determine how these factors may affect insect performance and population dynamics in a climate-change perspective; - spatial-temporal dynamics of the infestations during the different phases of the outbreak, in order to model bark beetle activity and behaviour; - effects of a sanitation felling on spot dynamics and damage level, in order to help management decisions making about whether to apply active control measures; - natural enemy complex associated with I. acuminatus, in order to assess the role of parasitoids and predators on population dynamics.
Il Coleottero Scolitide Ips acuminatus (Gyllenhal) (Coleoptera: Curculionidae, Scolytinae) ha recentemente causato estese e gravi infestazioni in diverse zone distribuite sull‟arco alpino e, tra queste, la valle del Boite (Dolomiti). Lo scolitide, per lungo tempo considerato di scarsa rilevanza economica, è stato recentemente incluso tra le dieci specie di insetti xilofagi più dannose in Europa in quanto sempre più frequentemente associato a fenomeni di elevata mortalità del pino silvestre. È noto che fattori abiotici quali elevata temperatura e stress idrico possono scatenare gravi infestazioni di I. acuminatus: per questo motivo è probabile che i cambiamenti climatici in atto aumentino i rischi cui possono essere soggette le pinete di pino silvestre, per l‟attività sia dell‟insetto da solo sia in associazione con parassiti opportunisti (secondari). Le gravi infestazioni segnalate negli ultimi anni sia sulle Alpi occidentali che su quelle orientali sembrano confermare tale ipotesi. I. acuminatus è specie ad areale euroasiatico ed è uno dei più comuni organismi xilofagi legati al pino silvestre (Pinus sylvestris). L‟insetto è poligamo e in un sistema di gallerie si possono trovare fino a 12 femmine associate a un singolo maschio. Le gallerie materne si irradiano da un vestibolo centrale scavato dal maschio, determinando un caratteristico „sistema a stella‟. Le uova sono deposte lungo entrambi i lati della galleria materna e le larve si sviluppano in brevi gallerie scavate nel floema, essendo la specie fleomicetofaga e comunemente associata a specie fungine funghi quali Ophiostoma brunneo-ciliatum e Ambrosiella macrospora. Prima di emergere dal materiale infestato, i giovani adulti necessitano di un periodo di maturazione che svolgono nutrendosi del floema situato nelle immediate vicinanze delle gallerie larvali e delle celle pupali in cui si sono sviluppati. A termine del periodo di maturazione, gli adulti sfarfallano e colonizzano i rami e la parte superiore dei fusti del pino silvestre, in quanto prediligono le parti con corteccia di spessore non superiore a 4-5 mm. Fonti bibliografiche riportano la specie come monovoltina in Scandinavia e bivoltina in Europa meridionale. I. acuminatus sverna allo stadio adulto principalmente nel materiale infestato in cui si è sviluppato; per le popolazioni nordiche la lettiera sembra costituire un ulteriore sito di svernamento. I primi voli primaverili hanno luogo quando la temperatura dell‟aria raggiunge i 14 -16°C, ma il picco dei voli si verifica quando questa supera i 18°C. Come molti altri scolitidi che adottano la strategia dell‟attacco massale al fine di vincere le difese dell‟ospite, le infestazioni di I. acuminatus si manifestano con attacchi diffusi e concentrati su un numero variabile di piante vicine tra loro, dando luogo a tipiche infestazioni definite a „macchia di leopardo‟. Durante il lavoro di ricerca, condotto in concomitanza al verificarsi di una grave pullulazione dello scolitide nelle Alpi sud-orientali, si è cercato di chiarire diversi aspetti poco noti della biologia dell‟insetto, dedicando particolare attenzione a: - voltinismo, fenologia e performance riproduttiva considerate in relazione a temperatura e densità di colonizzazione, allo scopo di determinare come questi fattori possano influire sulla performance e sulla dinamica di popolazione dell‟insetto nel quadro del cambiamento climatico; - dinamiche spazio-temporali dei nuclei di infestazione di I. acuminatus durante le diverse fasi della pullulazione, al fine di prevedere il grado di attività e il possibile comportamento futuro dell‟insetto; - impatto di tagli fitosanitari sulle dinamiche di popolazione ed effetti nel limitare i danni arrecati alle pinete, allo scopo di stabilire criteri di valutazione utili nella gestione dei boschi infestati; - complesso di nemici naturali associati a I. acuminatus, al fine di determinare quale ruolo e importanza possano avere parassitoidi e predatori sulla dinamica delle infestazioni.

2006/2007
Lo scopo di questa tesi di dottorato è la stima del moto forte del suolo nell’area delle Alpi Sud-Orientali. A tal fine sono state proposte delle relazioni empiriche che stimano i parametri del moto in funzione della magnitudo, della distanza dall’epicentro e della classificazione geologica del suolo; successivamente tali relazioni sono state usate per calibrare il software ShakeMaps con il fine di generare in tempo reale le mappe di scuotimento del terreno per la regione Friuli-Venezia Giulia. Le GMPEs (Ground Motion Predictive Equations) per PGA, PGV e SA sono state calcolate nell’area delle Alpi Sud-Orientali utilizzando registrazioni del moto forte del terreno. Sono state selezionate 900 forme d’onde accelerometriche filtrate tra 0.1 Hz e 30 Hz; la distanza epicentrale varia tra 1 km a 100 km, mentre la magnitudo locale, opportunamente calibrata confrontando diversi cataloghi, varia in un intervallo relativamente ampio (3.0 <= ML <= 6.3). Sono stati testati diversi modelli di attenuazione e il miglior risultato è stato individuato utilizzando specifici criteri di valutazione derivanti da considerazioni di carattere statistico (valore di R2, uso dell’ANOVA test, analisi dei residui). I coefficienti del modello finale sono stati determinati oltre che da ML, dalla distanza epicentrale e dagli effetti dovuti al sito, anche dalla saturazione della magnitudo, dalla correlazione tra magnitudo e distanza e dagli effetti di “near-source”. I coefficienti delle GMPEs sono stati calcolati per le componenti verticali ed orizzontali (rappresentata sia con la componente maggiore sia con la somma vettoriale delle due componenti); la tecnica dell’analisi dei gruppi ha permesso di ridurre l’incertezza finale sulle relazioni empiriche. Il confronto con i risultati ottenuti precedentemente evidenzia come le relazioni ottenute in questa tesi abbiano una maggiore attenuazione a basse magnitudo e a grandi distanze; risultati analoghi sono stati ottenuti per le relazioni ricavate dai dati registrati in tutta l’Italia Settentrionale. L’evoluzione recente delle reti sismiche rende oggi disponibile una grossa mole di dati acquisiti in tempo reale, per cui risulta fattibile stimare velocemente lo scuotimento del terreno tramite mappe; il software “ShakeMap” è stato adattato alle Alpi Sud-Orientali implementato allo scopo di ottenere una stabile interfaccia con il sistema di acquisizione dati “Antelope” che garantisca l’estrazione dei parametri del moto dalle forme d’onda e la creazione delle mappe di scuotimento entro 5 minuti dall’evento sismico. Questa procedura richiede una fitta e uniforme distribuzione spaziale degli strumenti di registrazione sul territorio e una classificazione geologica del suolo fatta usando le velocita’ medie, Vs30, dei primi 30m del mezzo immediatamente sotto gli strumenti. La classificazione geologica del suolo prevede la suddivisione in tre categorie (suolo rigido, suolo addensato e suolo soffice) mentre i coefficienti di amplificazione sono stati calcolati usando le relazioni proposte da Borcherdt (1994). Le relative mappe vanno calcolate usando le GMPEs e le relazioni empiriche che legano il moto del terreno all’intensità macrosismica, basate ambedue su dati registrati nella regione alpina. Le GMPEs discusse in precedenza sono state inserite nel software “ShakeMap” per la produzione delle mappe di scuotimento in tempo reale e quasi-reale nell’Italia Nord-Orientale. Per valutare l’effetto della densità di stazioni sulle mappe di scuotimento sono stati calcolati dei sismogrammi sintetici relativi al terremoto di Bovec 2004 variando il passo di griglia e la geometria dei ricevitori. I risultati ottenuti indicano come una distribuzione fitta e uniforme di strumenti sul territorio e una scelta accurata delle dimensioni della griglia dei ricevitori siano cruciali per calibrare le mappe di scuotimento in una ben determinata area geografica. Le mappe di scuotimento del suolo sono state generate per otto terremoti avvenuti nell’area considerata negli ultimi 30 anni; inoltre per gli eventi del Friuli 1976 e Bovec 1998 è stato utilizzato il modello di faglia finita con i parametri di sorgente stimati in precedenti studi. La validazione del modello è stata fatta calcolando il misfit tra le intensità macrosismiche osservate (catalogo DBMI04) e quelle “strumentali” che sono state ottenute dai sismogrammi sintetici tramite relazioni empiriche tra moto del suolo ed intensità. L’analisi è stata fatta per i terremoti del Cansiglio (1936), del Friuli (1976) e di Bovec (1998). I sismogrammi sintetici sono stati calcolati ad una frequenza massima di 10 Hz applicando il modello della riflettività; i parametri del moto sono stati estratti dai segnali sintetici calcolati nelle attuali stazioni di registrazione e successivamente sono state generate le mappe di scuotimento. L’intensità macrosismica “strumentale” è stata ricavata applicando diverse relazioni; il minor misfit è stato ottenuto usando le relazioni proposte da Kästli and Fäh (2006) per tutti e tre i terremoti considerati, il che sembra validare il nostro modello di Shake Maps.
The aim of this PhD thesis is to estimate ground motions in the South-Eastern Alps area. For this purpose we purposed empirical relationships that estimate the ground motion parameters as function of the magnitude, the epicentral distance and the soil geological characterization. Later on these relationships are used to calibrate the ShakeMaps software to generate ground motion shake maps in real time for the Friuli-Venezia Giulia region. The GMPEs (Ground Motion Predictive Equations) for PGA, PGV and SA are computed in the South-Eastern Alps area using strong motion observations. 900 accelerometric waveforms are selected and filtered between 0.1 Hz and 30 Hz; the epicentral distance varies from 1 km to 100 km, while the local magnitude, calibrated by comparison with various catalogues, varies in a relatively wide range (3.0 <= ML <= 6.3). Various attenuation models are tested and the best result is selected by the adoption of specific evaluation criteria derived from statistical considerations (R2 value, ANOVA test, residuals analysis). The coefficients of the final model are determined from ML, the epicentral distance, the site effects, the magnitude saturation, the correlation between the distance and the magnitude and the near-source effects. The coefficients of the GMPEs are computed from vertical and horizontal components (the latter represented both as the largest horizontal component and the vectorial addiction); the cluster analysis reduces the final uncertainties on the empirical relations. The comparison with the previous results evidences that the obtained relationships are characterized by a strong attenuation at low magnitudes and large distances. Similar results are obtained for the relationships derived from data recorded all over Northern Italy. The recent evolution of the seismic networks provides a large number of data, available in real time, so it is possible to quickly estimate shake maps. The “ShakeMap” software has been adapted to the South-Eastern Alps region and implemented to obtain a stable interface with the “Antelope” acquisition system in order to extract the ground motion parameters from the waveforms and the generation of the shake maps within 5 minutes from the earthquake occurrence. This procedure requires a dense and uniform spatial distribution of the recording instruments in the field and a geological classification of the soil derived from the average velocities of the S waves in the first 30m below the recording instruments (Vs30). In the geological classification the soil is divided into three classes (bedrock, stiff soil and soft soil), and the amplification coefficients are computed using the relationships proposed by Borcherdt (1994). The related maps are generated using the GMPEs and the empirical relations that predict the macroseismic intensity from the ground motion, both derived from data observed in the Alpine region. The GMPEs that are obtained in this thesis are inserted in the ShakeMap software to generate shake maps in real time or quasi real time in North-Eastern Italy. To evaluate the effects of the station coverage on the shake maps, synthetic seismograms are computed for the Bovec 2004 earthquake by varying the grid size and the network geometry. The results indicate that a dense and uniform spatial distribution in the field and a careful choice of the grid size are crucial to calibrate the shake maps in a given geographical area. The shake maps are generated for eight earthquakes occurred in the studied area in the last 30 years. Furthermore, the finite-fault model is utilized for the seismic events of the Friuli 1976 and Bovec 1998 selecting the source parameters proposed in previous studies. The model validation is done computing the misfit value between the observed macroseismic data (DBMI04 catalogue) and the “instrumental” intensities that are obtained from the synthetic seismograms using empirical relationships between the ground motion and intensity. This analysis has been done for the earthquakes of Cansiglio (1936), Friuli (1976) and Bovec (1998). The synthetic seismograms are calculated for an upper cutoff frequency of 10 Hz applying the reflectivity model. The ground motion parameters are extracted from synthetic signals computed at the presently operating seismic stations and the shake maps are generated. The macroseismic intensity is derived from various relationships; the lowest misfit is obtained using the relation proposed by Kästli and Fäh (2006) for all considered seismic events and this seem to validate our Shake Maps model.
XX Ciclo
1978

Wenn sich auch die ältesten Musikdokumente des Banats auf die reichen kirchenmusikalischen Traditionen dieser südosteuropäischen Grenzregion beziehen, so spielte trotzdem das Operntheater die wichtigste Rolle als Kulturfaktor und Multiplikator in der musikalischen Erziehung der bürgerlichen Gesellschaft. Die Oper feierte gleichzeitig einen triumphalen Einzug in die Banater Städte Temeswar, Arad, Lugosch, Orawitza, Reschitza und Werschetz.

Wenn sich auch die ältesten Musikdokumente des Banats auf die reichen kirchenmusikalischen Traditionen dieser südosteuropäischen Grenzregion beziehen, so spielte trotzdem das Operntheater die wichtigste Rolle als Kulturfaktor und Multiplikator in der musikalischen Erziehung der bürgerlichen Gesellschaft. Die Oper feierte gleichzeitig einen triumphalen Einzug in die Banater Städte Temeswar, Arad, Lugosch, Orawitza, Reschitza und Werschetz.

Australian Alps is a fascinating guide to Kosciuszko, Alpine and Namadgi National Parks. It introduces the reader to some of Australia’s highest mountains, their climate, geology and soils, plants and animals and their human history. It traces the long-running conflicts between successive users of the mountains and explores the difficulties in managing the land for nature conservation. The book gives credit to little-known or understood stories of the people who have worked to establish better understanding of the Alps, especially their vital role as the major water catchments for south-eastern Australia. This new edition updates many themes, including the involvement of Aboriginal people in the region, catchment function and condition, pest plants and animals, fire and the issue of climate change. Written by a specialist with over 25 years’ experience in community education in and about the Australian Alps National Parks, this new edition features many excellent natural history and historical photographs. Ideal as support information for field trips, it will make a wonderful memento of an alpine visit. This book acts as a detailed companion to park interpretive material and to topic-specific field guides: it caters for readers who want a broad overview of areas of interest they will come across in a visit to the mountains.

The Australian Capital Territory is a treasure trove for naturalists, despite being without a coastline, without rainforest or without deserts. A wealth of biodiversity is found there, due to the close proximity of three major habitat types: the great western woodland grassy plains bump up against the inland edge of the coastal hinterland mountain forests, while the whole south-eastern Australian Alps system reaches its northern limit in the Brindabella Ranges. Each of these habitats has its own rich suite of plants and animals, so a great diversity of life can be found within an hour’s drive of Parliament House. A Bush Capital Year introduces the fauna, flora, habitats and reserves of the Australian Capital Territory and includes the most recent research available. It also emphasises often unappreciated or even unrecognised urban wildlife. For each month of the year there are 10 stories which discuss either a species or a group of species, such as mosses and mountain grasshoppers. While never anthropomorphic, many of the stories are written from the organism’s point of view, while others are from that of an observer. Beautiful paintings complement the text and allow better visualisation of the stories and the subjects. 2011 Whitley Award Commendation for Regional Natural History.

To interpret the legal–geographical dimension of the subject indicated in the title, it is necessary to know that medieval Europe was divided into north–south, roughly as the countries north and south of the Alps. The term ‘Central and Eastern Europe’ is a modern concept that cannot simply be projected back to the Middle Ages. The legal institutions discussed in this chapter have affected the territories of present-day Bavaria, Austria, Slovakia, Slovenia, Croatia, Serbia, and Poland, to a greater or lesser extent. In terms of the medieval ecclesiastical judiciary, this area encompassed both European legal regions, as in the German and Polish territories, the northern type of official judiciary prevailed, while the procedure utilized in the Kingdom of Hungary’s ecclesiastical court can be classified as the southern vicarian judiciary. It is important to emphasize, however, that a number of combined elements from the two judging models can also be detected, and I will elaborate on these features in detail in this chapter. The ecclesiastical judiciary focused on the dioceses, so organizational and jurisdictional rules are included in its main elements in the study. The more detailed section of the Bavarian judiciary presents all important litigants. When discussing institutions in Poland and Hungary, I also tried to highlight the parallels and differences that can be related to each other, and thus, the chapter engages in a comparative discussion of the institutions of ecclesiastical justice in Central and Eastern Europe, as promised in the title.

Hillslopes are the dominant landform features of the Earth’s surface. They make up the interface between the atmosphere and Earth systems, providing a substrate that supports life and thus the basis for human activities within the Mediterranean. Their location at this interface means that hillslopes evolve through a complex interaction of different processes, operating at a range of different time and spatial scales. At longer timescales, processes of weathering convert rock and other parent materials into soils. Soils allow the growth of vegetation and thus further feedbacks between atmospheric and surface processes; in some cases these feedbacks can be seen to provide relative stability, while in others the system can become more fragile (Chapter 20). The latter case often arises as a result of erosion processes of various types. Water erosion and mass movements are a significant element of Mediterranean landscape evolution, occurring in parallel with (in response to, and affecting) tectonic processes that have moulded the configuration of the Earth’s crust (see Chapter 1), producing the unique combination of environmental characteristics of the region. Since the Late Pleistocene, depending on location, human activity has led to an acceleration of many of these processes, with important consequences for the basic ‘life-support system’ of the region and for global environmental cycles. The in situ modification of near-surface materials is typically considered to take place along a continuum relating to the dominance of mechanical or chemical processes (e.g. Birkeland 1999). The simplest control may be considered to be climatic, with mechanical breakdown of particles dominating in cold, dry conditions, and chemical processes dominating in warm, wet conditions. Comparing this model to the present day climate of the Mediterranean suggests, as with other processes, something of a north–south divide in terms of the dominant weathering process. The northern part of the basin (together with the Levant and the north-facing uplands of the Maghreb) would seem to be dominated by moderate chemical weathering; exceptions being the arid areas of south-east Spain, southern Sicily, eastern Cyprus, and parts of the Anatolian plateau as well as areas where low average temperatures would also reduce rates, such as in the Alps and parts of Slovenia and Croatia.

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.