scholarly journals Seismological observations in Antarctica

2019 ◽  
Vol 1 (1) ◽  
pp. 11-22
Author(s):  
Oleg Starovoit ◽  
Aleksei Malovichko ◽  
Svetlana Poygina ◽  
Dmitrii Badalyan ◽  
Vladimir Krumpan ◽  
...  
Keyword(s):  
Seismic Station ◽  
Ice Sheet ◽  
Seismic Zone ◽  
Seismic Stations ◽  
Monitoring Period ◽  
Local Earthquakes ◽  
History Of ◽  
Instrumental Monitoring ◽  
The Antarctic ◽  
Digital Equipment

The history of seismological observations development in Antarctica is shown. Maps of the existing seismic stations and earthquake epicenters location on the mainland territory for the instrumental monitoring period (1956–2018) are presented according to data from International centers. Russian seismic stations monitor major earthquakes around the globe, earthquakes in the seismic zone around Antarctica, and local seismic phenomena in Antarctica, including local earthquakes and ice sheet ruptures. Since 1999, the Novolazarevskaya seismic station has been equipped with digital equipment. An analysis of the sixth continent seismicity was made; the records of the Antarctic strongest earthquakes (2007, 2008, and 2012) by the GS RAS stations Mirny and Novolazarevskaya were shown.

scholarly journals Preserved landscapes underneath the Antarctic Ice Sheet reveal the geomorphological history of Jutulstraumen Basin

2021 ◽  
Author(s):  
Steven Franke ◽  
Hannes Eisermann ◽  
Wilfried Jokat ◽  
Graeme Eagles ◽  
Jölund Asseng ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
History Of ◽  
The Antarctic

PISM paleo simulations of the Antarctic Ice Sheet over the last two glacial cycles

2020 ◽  
Author(s):  
Torsten Albrecht ◽  
Ricarda Winkelmann ◽  
Anders Levermann
Keyword(s):  
Boundary Conditions ◽  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Changes ◽  
Glacial Cycles ◽  
Antarctic Ice Sheet ◽  
History Of ◽  
Global Sea Level ◽  
Glacial Time ◽  
The Antarctic

<p>Simulations of the glacial-interglacial history of the Antarctic Ice Sheet provide insights into dynamic threshold behavior and estimates of the ice sheet's contributions to global sea-level changes, for the past, present and future. However, boundary conditions are weakly constrained, in particular at the interface of the ice-sheet and the bedrock. We use the Parallel Ice Sheet Model (PISM) to investigate the dynamic effects of different choices of input data and of various parameterizations on the sea-level relevant ice volume. We evaluate the model's transient sensitivity to corresponding parameter choices and to different boundary conditions over the last two glacial cycles and provide estimates of involved uncertainties. We also present isolated and combined effects of climate and sea-level forcing on glacial time scales. </p>

Progress report on the Antarctic ice sheet

Polar Record ◽  
1960 ◽  
Vol 10 (64) ◽  
pp. 3-10 ◽  
Author(s):  
G. de Q. Robin
Keyword(s):  
Sea Level ◽  
Ross Sea ◽  
Ice Sheet ◽  
Great Depth ◽  
Progress Report ◽  
The Other ◽  
The Past ◽  
History Of ◽  
Antarctic Continent ◽  
The Antarctic

The art, science and sport of conducting scientific traverses across the Antarctic continent has advanced so rapidly during the past decade that we are making considerable progress towards understanding the main characteristics of that continent and its ice mantle. Many reports of recent work are provisional, so some changes of detail in the following account may eventually prove necessary. Nevertheless, some major features are now well established, such as the great depth of the subglacial floor to the east of the Ross Sea, and the observations that show considerable sections of the rock of East Antarctica† to be above sea level. On the other hand, the past glaciological history of the continent and the state of the present mass balance of the ice sheet still need much more investigation before we can be satisfied with the answers. The continued activity in Antarctica should result in our knowledge of the continent advancing much further during the coming decade.

scholarly journals Formation and disintegration of the Antarctic ice sheet

1994 ◽  
Vol 20 ◽  
pp. 336-340 ◽  
Author(s):  
Philippe Huybrechts
Keyword(s):  
Temperature Rise ◽  
Ice Sheet ◽  
Climatic Conditions ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
Late Neogene ◽  
History Of ◽  
The Antarctic ◽  
East Antarctic Ice Sheet

A model of the Antarctic ice sheet has been used to simulate the ice sheet in warmer climates, in order to investigate what kind of ice-sheet geometries one can reasonably expect under what kind of climatic conditions and to discover which physical mechanisms may be involved to explain them. The results of these experiments reveal the considerable stability of; in particular, the East Antarctic ice sheet. It would require a temperature rise of between 17 and 20 K above present levels to remove this ice sheet from the subglacial basins in the interior of the continent and of 25 K to melt down the Antarctic ice sheet completely. For a temperature rise below 5 K, the model actually predicts a larger Antarctic ice sheet than today as a result of increased snowfall, whereas the west Antarctic ice sheet was round not to survive temperatures more than 8–10 K above present values. Furthermore, basal temperature conditions in these experiments point to the problems involved in raising the base of the ice sheet to the pressure-melting point over the large areas necessary to consider the possibility of sliding instability. These results bear on a lively debate regarding the late Cenozoic glacial history of Antarctica. Particularly, based on these findings, it is difficult to reconcile a highly variable East Antarctic ice sheet until the Pliocene with modest warming recorded in, for instance, the deep-sea records for the late Neogene.

Approach to study the seismicity in the Perunica Glacier, Livingston Island, Antarctica

2021 ◽  
Author(s):  
Gergana Georgieva ◽  
Liliya Dimitrova ◽  
Dragomir Dragomirov
Keyword(s):  
Seismic Activity ◽  
Seismic Noise ◽  
Seismic Station ◽  
Velocity Model ◽  
Noise Power ◽  
Noise Sources ◽  
Seismic Stations ◽  
Glacial Origin ◽  
Livingston Island ◽  
The Antarctic

<p>The seismicity caused by the movement of glaciers was discovered only 30-40 years ago, and it was initially assumed that only glaciers in Greenland create this type of seismicity. Today, a significant part of the earthquakes registered by the Antarctic seismic stations are of glacial origin. In recent years, scientists' interest in studying the seismic activity of glaciers and its relationship to various environmental factors has increased due to the response of the ice mass to climate change.</p><p>The interest of studying seismicity of Antarctica has increased in the last decade with installation of a growing number of seismic stations in the region.</p><p>In 2015, with the first installation of the LIVV seismic station, Bulgarian seismologists began studying the seismicity of the Perunika Glacier, located on Livingston Island, Antarctica. Between 2015 and 2018, seismic recordings were made only in the astral summer, and from January 2020 the seismic station was installed for year-round operation. The seismic station is located near the glacier.</p><p>In this study, an approach to analyze the ice generated events recorded during all working period of the LIVV station is presented. Depending on the source mechanism and therefore the different waveform shapes, several types of icequakes and earthquakes are distinguished.</p><p><span>Registered icequakes are more than 16000. Its duration varies between less than a second and more than a minute. A few events are several minutes long. We</span> <span>have noticed that from 2015 to 2020, the number of glacier events is increasing while its duration is decreasing. </span></p><p>Localization of the ice generated events with duration below 1 s is calculated. In the localization procedure, a velocity model developed for the area of the seismic station is applied. The produced icequake epicenters are grouped in several clusters within the Perunika glacier. The nature of these glacier events are still studying.</p><p><span>Another approach to study the seismic activity of the glacier is carried out by estimating the ambient seismic noise. Frequent and spectral distribution of the power of seismic noise is made over the seismic data recorded during all working periods. It is concluded that </span><span>t</span>he noise sources in the periods around 0.5 s are linked to the dynamic processes in the Perunika Glacier<span>.</span> Some relationship between the change in <span>the </span>noise power in the 0.2-0.6s period band and tidal cycles has been found.</p><p><span><strong>Acknowledgment:</strong></span><span> The presented study is supported by project: No 70.25-171/22.11.2019 “Study the activity of the Perunika glacier during year-round deployment” funded by the </span><span>National Center for Polar Studies, Bulgaria</span><span>.</span></p>

Late Tertiary history of the Antarctic ice sheet: Evidence from the Dry Valleys

Geology ◽  
1984 ◽  
Vol 12 (5) ◽  
pp. 263 ◽  
Author(s):  
George H. Denton ◽  
Michael L. Prentice ◽  
Davida E. Kellogg ◽  
Thomas B. Kellogg
Keyword(s):  
Ice Sheet ◽  
Dry Valleys ◽  
Antarctic Ice Sheet ◽  
Late Tertiary ◽  
History Of ◽  
The Antarctic

scholarly journals Formation and disintegration of the Antarctic ice sheet

1994 ◽  
Vol 20 ◽  
pp. 336-340 ◽  
Author(s):  
Philippe Huybrechts
Keyword(s):  
Temperature Rise ◽  
Ice Sheet ◽  
Climatic Conditions ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
Late Neogene ◽  
History Of ◽  
The Antarctic ◽  
East Antarctic Ice Sheet

A model of the Antarctic ice sheet has been used to simulate the ice sheet in warmer climates, in order to investigate what kind of ice-sheet geometries one can reasonably expect under what kind of climatic conditions and to discover which physical mechanisms may be involved to explain them. The results of these experiments reveal the considerable stability of; in particular, the East Antarctic ice sheet. It would require a temperature rise of between 17 and 20 K above present levels to remove this ice sheet from the subglacial basins in the interior of the continent and of 25 K to melt down the Antarctic ice sheet completely. For a temperature rise below 5 K, the model actually predicts a larger Antarctic ice sheet than today as a result of increased snowfall, whereas the west Antarctic ice sheet was round not to survive temperatures more than 8–10 K above present values. Furthermore, basal temperature conditions in these experiments point to the problems involved in raising the base of the ice sheet to the pressure-melting point over the large areas necessary to consider the possibility of sliding instability. These results bear on a lively debate regarding the late Cenozoic glacial history of Antarctica. Particularly, based on these findings, it is difficult to reconcile a highly variable East Antarctic ice sheet until the Pliocene with modest warming recorded in, for instance, the deep-sea records for the late Neogene.

scholarly journals Links between CO<sub>2</sub>, glaciation and water flow: reconciling the Cenozoic history of the Antarctic Circumpolar Current

2014 ◽  
Vol 10 (3) ◽  
pp. 2397-2416 ◽  
Author(s):  
J.-B. Ladant ◽  
Y. Donnadieu ◽  
C. Dumas
Keyword(s):  
Antarctic Circumpolar Current ◽  
Ice Sheet ◽  
Late Eocene ◽  
Early Oligocene ◽  
History Of ◽  
Potential Impact ◽  
Circumpolar Current ◽  
Set Up ◽  
The Antarctic ◽  
Exact Timing

Abstract. The timing of the onset of the Antarctic Circumpolar Current (ACC) is a crucial event of the Cenozoic because of its cooling and isolating effect over Antarctica. It is intimately related to the glaciations occurring throughout the Cenozoic from the Eocene–Oligocene (EO) transition (≈34 Ma) to the middle Miocene glaciations (≈13.9 Ma). However, the exact timing of the onset remains debated with evidence for a late Eocene set up contradicting others data pointing to an occurrence closer to the Oligocene–Miocene (OM) boundary. In this study, we show the potential impact of the Antarctic ice sheet on the initiation of a proto-ACC at the EO boundary. Our results reveal that the regional cooling effect of the ice sheet increases the sea ice formation, which disrupts the meridional density gradient in the Southern Ocean and leads to the onset of a circumpolar current and its progressive strengthening. We also suggest that subsequent variations in atmospheric CO2, ice sheet volumes and tectonic reorganizations may have affected the ACC intensity after the Eocene–Oligocene transition, which in turn may provide an explanation for the second initiation of the ACC at the Oligocene–Miocene boundary and may reconcile evidence supporting both early Oligocene and early Miocene onset of the ACC.

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