A 25.6 m long firn core extracted from the Grímsvötn ice shelf in June 1993

JOKULL ◽  
2020 ◽  
pp. 157-159
Author(s):  
Magnús Tumi Gudmundsson ◽  
Jósef Hólmjárn
Keyword(s):  
2014 ◽  
Vol 119 (11) ◽  
pp. 6549-6562 ◽  
Author(s):  
E. Schlosser ◽  
H. Anschütz ◽  
D. Divine ◽  
T. Martma ◽  
A. Sinisalo ◽  
...  

2017 ◽  
Author(s):  
Vikram Goel ◽  
Joel Brown ◽  
Kenichi Matsuoka

Abstract. The Dronning Maud Land coast in East Antarctica has numerous ice rises that very likely control the dynamics and mass balance of this region. However, only a few of these ice rises have been investigated in detail. Here, we report field measurements of Blåskimen Island, an isle-type ice rise adjacent to the Fimbul Ice Shelf. Blåskimen Island is largely dome shaped, with a pronounced ridge extending to the southwest from its summit (410 m a.s.l.). Its bed is mostly flat and about 100 m below the current sea level. Shallow radar-detected isochrones dated with a firn core reveal that the surface mass balance is higher on the southeastern slope than the northwestern slope by ~ 37 %, and this pattern has persisted for at least the past decade. Radar stratigraphy shows upward arches underneath the summit, indicating that the summit position has been stable over at least one characteristic time of this ice rise (~ 600 years). Ensemble estimates of the mass balance using the input-output method show that this ice rise has thickened by 0.07–0.35 m ice equivalent per year over the past decade.


Erdkunde ◽  
1970 ◽  
Vol 24 (2) ◽  
pp. 144-145 ◽  
Author(s):  
Fritz Loewe
Keyword(s):  

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 155
Author(s):  
Fiorenza Torricella ◽  
Romana Melis ◽  
Elisa Malinverno ◽  
Giorgio Fontolan ◽  
Mauro Bussi ◽  
...  

The continental margin is a key area for studying the sedimentary processes related to the advance and retreat of the Ross Ice Shelf (Antarctica); nevertheless, much remains to be investigated. The aim of this study is to increase the knowledge of the last glacial/deglacial dynamics in the Central Basin slope–basin system using a multidisciplinary approach, including integrated sedimentological, micropaleontological and tephrochronological information. The analyses carried out on three box cores highlighted sedimentary sequences characterised by tree stratigraphic units. Collected sediments represent a time interval from 24 ka Before Present (BP) to the present time. Grain size clustering and data on the sortable silt component, together with diatom, silicoflagellate and foraminifera assemblages indicate the influence of the ice shelf calving zone (Unit 1, 24–17 ka BP), progressive receding due to Circumpolar Deep Water inflow (Unit 2, 17–10.2 ka BP) and (Unit 3, 10.2 ka BP–present) the establishment of seasonal sea ice with a strengthening of bottom currents. The dominant and persistent process is a sedimentation controlled by contour currents, which tend to modulate intensity in time and space. A primary volcanic ash layer dated back at around 22 ka BP is correlated with the explosive activity of Mount Rittmann.


2020 ◽  
pp. 1-14
Author(s):  
Richard D. Ray ◽  
Kristine M. Larson ◽  
Bruce J. Haines

Abstract New determinations of ocean tides are extracted from high-rate Global Positioning System (GPS) solutions at nine stations sitting on the Ross Ice Shelf. Five are multi-year time series. Three older time series are only 2–3 weeks long. These are not ideal, but they are still useful because they provide the only in situ tide observations in that sector of the ice shelf. The long tide-gauge observations from Scott Base and Cape Roberts are also reanalysed. They allow determination of some previously neglected tidal phenomena in this region, such as third-degree tides, and they provide context for analysis of the shorter datasets. The semidiurnal tides are small at all sites, yet M2 undergoes a clear seasonal cycle, which was first noted by Sir George Darwin while studying measurements from the Discovery expedition. Darwin saw a much larger modulation than we observe, and we consider possible explanations - instrumental or climatic - for this difference.


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