Contourite Drifts in the Tartar Strait,Sea of Japan     

Baranov  B. V.  Lobkovsky  L. I.  Rukavishnikova  D. D.  Dozorova  K. A. 《Doklady Earth Sciences》2020,491(1):160-163

Doklady Earth Sciences - Contourite drifts were first detected in the Tatar Strait in the framework of the Sakhalin Slope Gas Hydrates International Project (2012–2015). The number of...  相似文献   

Forecasting aftershock activity: 2. Estimating the area prone to strong aftershocks     

S. V. Baranov  P. N. Shebalin 《Izvestiya Physics of the Solid Earth》2017,53(3):366-384

The technique for forecasting the spatial domain where fairly intense aftershocks should be expected after a strong earthquake is considered. The paper presents the task of estimating the area prone to the strong future aftershocks using the data for the first 12 h after the main shock. The existing aftershock identification techniques are inapplicable to this task because they either analyze the distributions of the epicenters of the aftershock process that has been already completed or only consider the parameters of the main shock and only provide rough estimates. Using the developed criteria of estimating the quality of the prediction, we quantitatively compared quite a few different candidates. The latter included the main known techniques and their modifications suggested by us. In these modifications, we took into account the results of the recent studies on the dynamics of the aftershock process. This enabled us to select the optimal procedure which demonstrated the best results of the quantitative tests for more than 120 aftershock sequences with the magnitudes starting from 6.5 all over the world. This procedure can be used in the seismological monitoring centers for forecasting the area prone to the aftershock activity after a strong earthquake based on the data of operative processing.  相似文献   

Combined Gravimetric–Seismic Crustal Model for Antarctica     

Alexey Baranov  Robert Tenzer  Mohammad Bagherbandi 《Surveys in Geophysics》2018,39(1):23-56

The latest seismic data and improved information about the subglacial bedrock relief are used in this study to estimate the sediment and crustal thickness under the Antarctic continent. Since large parts of Antarctica are not yet covered by seismic surveys, the gravity and crustal structure models are used to interpolate the Moho information where seismic data are missing. The gravity information is also extended offshore to detect the Moho under continental margins and neighboring oceanic crust. The processing strategy involves the solution to the Vening Meinesz-Moritz’s inverse problem of isostasy constrained on seismic data. A comparison of our new results with existing studies indicates a substantial improvement in the sediment and crustal models. The seismic data analysis shows significant sediment accumulations in Antarctica, with broad sedimentary basins. According to our result, the maximum sediment thickness in Antarctica is about 15 km under Filchner-Ronne Ice Shelf. The Moho relief closely resembles major geological and tectonic features. A rather thick continental crust of East Antarctic Craton is separated from a complex geological/tectonic structure of West Antarctica by the Transantarctic Mountains. The average Moho depth of 34.1 km under the Antarctic continent slightly differs from previous estimates. A maximum Moho deepening of 58.2 km under the Gamburtsev Subglacial Mountains in East Antarctica confirmed the presence of deep and compact orogenic roots. Another large Moho depth in East Antarctica is detected under Dronning Maud Land with two orogenic roots under Wohlthat Massif (48–50 km) and the Kottas Mountains (48–50 km) that are separated by a relatively thin crust along Jutulstraumen Rift. The Moho depth under central parts of the Transantarctic Mountains reaches 46 km. The maximum Moho deepening (34–38 km) in West Antarctica is under the Antarctic Peninsula. The Moho depth minima in East Antarctica are found under the Lambert Trench (24–28 km), while in West Antarctica the Moho depth minima are along the West Antarctic Rift System under the Bentley depression (20–22 km) and Ross Sea Ice Shelf (16–24 km). The gravimetric result confirmed a maximum extension of the Antarctic continental margins under the Ross Sea Embayment and the Weddell Sea Embayment with an extremely thin continental crust (10–20 km).  相似文献   

Middle Pleistocene environments,landscapes and tephrostratigraphy of the Armenian Highlands: evidence from Bird Farm 1, Hrazdan Valley     

Jenni E. Sherriff  Keith N. Wilkinson  Poppy Harding  Hayley Hawkins  Rhys G. O. Timms  Daniel S. Adler  Emily J. Beverly  Simon P. E. Blockley  Boris Gasparyan  Christina J. Manning  Darren Mark  Samvel Nahapetyan  Katie J. Preece 《第四纪科学杂志》2022,37(1):6-27

The significance of the southern Caucasus in understanding Pleistocene hominin expansions is well established. However, the palaeoenvironments in which Palaeolithic occupation of the region took place are presently poorly defined. The Hrazdan river valley, Armenian Highlands, contains a rich Palaeolithic record alongside Middle Pleistocene volcanic, fluvial and lacustrine strata, and thus offer exciting potential for palaeoenvironmental reconstruction. We present the first results of sedimentological, geochemical, tephrostratigraphical and biological (diatoms) study of the sequence of Bird Farm 1, located in the central part of the valley. These data show six phases of landscape development during the interval 440–200 ka. The sequence represents the first quantitative Pleistocene diatom record from the Armenian Highlands and the southern Caucasus, and indicates the persistence of a deep, stratified lacustrine system, with evidence for changing lake productivity that is tentatively linked to climate. Furthermore, major element chemical characterization of visible and crypto-tephra horizons in the sequence enables the first stages of the development of a regional tephrostratigraphy. Together, the evidence from Bird Farm 1 demonstrates the importance of lacustrine archives in the region for palaeoenvironmental reconstruction and highlights the potential for linkages between archives on both a local and regional scale.  相似文献