. (2013). Tide-induced microseismicity in the Mertz glacier grounding area, East Antarctica
. Geophysical Research Letters, 40(20), 5412–5416.
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Bai L, Ritsema J, . (2013). The effect of large-scale shear-velocity heterogeneity on SS precursor amplitudes
. Geophysical Research Letters, 40(23), 6054–6058.
Keywords: mantle transition zone, SS precursors, velocity heterogeneity, amplitude, 1734 Seismology, 7290 Computational seismology, 8124 Earth's interior: composition and state,
Programme: 133
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Bekki S, Rap A, Poulain V, Dhomse S, Marchand M, Lefevre F, Forster PM, Szopa S, Chipperfield MP, . (2013). Climate impact of stratospheric ozone recovery
. Geophysical Research Letters, 40(11), 2796–2800.
Keywords: stratospheric ozone, climate, 0340 Middle atmosphere: composition and chemistry,
Programme: 209
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. (2014). Ten year recurrence time between two major earthquakes affecting the same fault segment
. Geophysical Research Letters, 41(7), 2312–2318.
Keywords: earthquake recurrence, rerupture, seismic gap hypothesis, dynamic stress, Scotia, 7215 Earthquake source observations, 7223 Earthquake interaction, forecasting, and prediction, 7203 Body waves, 7209 Earthquake dynamics, 7250 Transform faults,
Programme: 133
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Lynner Colton, Long Maureen D, . (2014). Lowermost mantle anisotropy and deformation along the boundary of the African LLSVP
. Geophysical Research Letters, 41(10), 3447–3454.
Abstract: Shear wave splitting of SK(K)S phases is often used to examine upper mantle anisotropy. In specific cases, however, splitting of these phases may reflect anisotropy in the lowermost mantle. Here we present SKS and SKKS splitting measurements for 233 event-station pairs at 34 seismic stations that sample D″ beneath Africa. Of these, 36 pairs show significantly different splitting between the two phases, which likely reflects a contribution from lowermost mantle anisotropy. The vast majority of discrepant pairs sample the boundary of the African large low shear velocity province (LLSVP), which dominates the lower mantle structure beneath this region. In general, we observe little or no splitting of phases that have passed through the LLSVP itself and significant splitting for phases that have sampled the boundary of the LLSVP. We infer that the D″ region just outside the LLSVP boundary is strongly deformed, while its interior remains undeformed (or weakly deformed).
Keywords: lowermost mantle anisotropy, African LLSVP, discrepant SKS-SKKS splitting, 7208 Mantle, 7203 Body waves,
Programme: 133
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. (2020). Antarctic Ozone Enhancement During the 2019 Sudden Stratospheric Warming Event (Vol. 47).
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. (2014). Evidence for a differential sea level rise between hemispheres over the twentieth century (Vol. 41).
Abstract: AbstractTide gauge records are the primary source of sea level information over multidecadal to century timescales. A critical issue in using this type of data to determine global climate-related contributions to sea level change concerns the vertical motion of the land upon which the gauges are grounded. Here we use observations from the Global Positioning System for the correction of this vertical land motion. As a result, the spatial coherence in the rates of sea level change during the twentieth century is highlighted at the local and the regional scales, ultimately revealing a clearly distinct behavior between the Northern and the Southern Hemispheres with values of 2.0 mm/yr and 1.1 mm/yr, respectively. Our findings challenge the widely accepted value of global sea level rise for the twentieth century.
Keywords: climate change geodesy GPS land motion sea level tide gauge
Programme: 688
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E. Pauthenet, F. Roquet, G. Madec, C. Guinet, M. Hindell, C. R. McMahon, R. Harcourt, D. Nerini. (2018). Seasonal Meandering of the Polar Front Upstream of the Kerguelen Plateau (Vol. 45).
Abstract: The location of the Antarctic Polar Front (PF) is mapped in the Southern Indian Ocean by decomposing the shape of temperature and salinity profiles into vertical modes using a functional Principal Component Analysis. We define the PF as the northernmost minimum of temperature at the subsurface and represent it as a linear combination of the first three modes. This method is applied on an ocean reanalysis data set and on in situ observations, revealing a seasonal variability of the PF latitudinal position that is most pronounced between the Conrad Rise and the Kerguelen Plateau. This shift coincides with variations in the transport across the Northern Kerguelen Plateau. We suggest that seasonal changes of the upper stratification may drive the observed variability of the PF, with potentially large implications for the pathways and residence time of water masses over the plateau and the phytoplankton bloom extending southeast of the Kerguelen Islands.
Keywords: Antarctic Polar Front functional principal component analysis Kerguelen Plateau Southern Indian Ocean Southern Ocean fronts
Programme: 1201
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. (2021). Present and Future of Rainfall in Antarctica (Vol. 48). Bachelor's thesis, , .
Abstract: While most precipitation in Antarctica falls as snow, little is known about liquid precipitation, although it can have ecological and climatic impacts. This study combines meteorological reports at 10 stations with the ERA5 reanalysis to provide a climatological characterization of rainfall occurrence over Antarctica. Along the East Antarctic coast, liquid precipitation occurs 22 days per year at most and coincides with maritime intrusions and blocking anticyclones. Over the north-western Antarctic Peninsula, rainfall occurs more than 50 days per year on average and the recent summer cooling was accompanied by a decrease of ?35 annual rainy days per decade between 1998 and 2015 at Faraday-Vernadsky. Projections from seven latest-generation climate models reveal that Antarctic coasts will experience a warming and more frequent and intense rainfall by the end of the century. Rainfall is expected to impact new regions of the continent, increasing their vulnerability to melting by the preconditioning of surface snow.
Programme: 1013,1143
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. (2019). Dynamic Fine-Scale Sea Icescape Shapes Adult Emperor Penguin Foraging Habitat in East Antarctica (Vol. 46). Bachelor's thesis, , .
Abstract: The emperor penguin, an iconic species threatened by projected sea ice loss in Antarctica, has long been considered to forage at the fast ice edge, presumably relying on large/yearly persistent polynyas as their main foraging habitat during the breeding season. Using newly developed fine-scale sea icescape data and historical penguin tracking data, this study for the first time suggests the importance of less recognized small openings, including cracks, flaw leads and ephemeral short-term polynyas, as foraging habitats for emperor penguins. The tracking data retrieved from 47 emperor penguins in two different colonies in East Antarctica suggest that those penguins spent 23% of their time in ephemeral polynyas and did not use the large/yearly persistent, well-studied polynyas, even if they occur much more regularly with predictable locations. These findings challenge our previous understanding of emperor penguin breeding habitats, highlighting the need for incorporating fine-scale seascape features when assessing the population persistence in a rapidly changing polar environment.
Keywords: emperor penguin fast ice foraging ecology iceberg polynya sea ice
Programme: 109,394,1091
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