Semiannual Oscillation of the Lunar Exosphere: Implications for Water and Polar Ice

2018 ◽  
Vol 45 (15) ◽  
pp. 7409-7416 ◽  
Author(s):  
R. Richard Hodges
Keyword(s):  
Polar Ice ◽  
Lunar Exosphere ◽  
Semiannual Oscillation

Untangling the Origin of Molecular Hydrogen in the Lunar Exosphere

2019 ◽  
Vol 887 (1) ◽  
pp. 27
Author(s):  
Parker B. Crandall ◽  
Jeffrey J. Gillis-Davis ◽  
Ralf I. Kaiser
Keyword(s):  
Molecular Hydrogen ◽  
Lunar Exosphere

Shallow-Layers-Detection Ice Sounding Radar for Mapping of Polar Ice Sheets

2021 ◽  
pp. 1-10
Author(s):  
Bo Zhao ◽  
Yueyi Zhang ◽  
Shinan Lang ◽  
Yan Liu ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Ice Sheets ◽  
Polar Ice ◽  
Polar Ice Sheets

scholarly journals Ice-Breaking Fleets of the United States and Canada: Assessing the Current State of Affairs and Future Plans

2021 ◽  
Vol 13 (2) ◽  
pp. 703
Author(s):  
Megan Drewniak ◽  
Dimitrios Dalaklis ◽  
Anastasia Christodoulou ◽  
Rebecca Sheehan
Keyword(s):  
United States ◽  
The United States ◽  
Maritime Transportation ◽  
The Arctic ◽  
Polar Ice ◽  
Northwest Passage ◽  
Ice Cap ◽  
Ice Coverage ◽  
Current State ◽  
State Of Affairs

In recent years, a continuous decline of ice-coverage in the Arctic has been recorded, but these high latitudes are still dominated by earth’s polar ice cap. Therefore, safe and sustainable shipping operations in this still frozen region have as a precondition the availability of ice-breaking support. The analysis in hand provides an assessment of the United States’ and Canada’s polar ice-breaking program with the purpose of examining to what extent these countries’ relevant resources are able to meet the facilitated growth of industrial interests in the High North. This assessment will specifically focus on the maritime transportation sector along the Northwest Passage and consists of four main sections. The first provides a very brief description of the main Arctic passages. The second section specifically explores the current situation of the Northwest Passage, including the relevant navigational challenges, lack of infrastructure, available routes that may be used for transit, potential choke points, and current state of vessel activity along these routes. The third one examines the economic viability of the Northwest Passage compared to that of the Panama Canal; the fourth and final section is investigating the current and future capabilities of the United States’ and Canada’s ice-breaking fleet. Unfortunately, both countries were found to be lacking the necessary assets with ice-breaking capabilities and will need to accelerate their efforts in order to effectively respond to the growing needs of the Arctic. The total number of available ice-breaking assets is impacting negatively the level of support by the marine transportation system of both the United States and Canada; these two countries are facing the possibility to be unable to effectively meet the expected future needs because of the lengthy acquisition and production process required for new ice-breaking fleets.

scholarly journals The duration of the active phase on surge-type glaciers: contrasts between Svalbard and other regions

1991 ◽  
Vol 37 (127) ◽  
pp. 388-400 ◽  
Author(s):  
Julian A. Dowdeswell ◽  
Gordon S. Hamilton ◽  
Jon Ove Hagen
Keyword(s):  
Time Series ◽  
North America ◽  
Active Phase ◽  
Aerial Photographs ◽  
Polar Ice ◽  
Phase Duration ◽  
Field Surveys ◽  
The World ◽  
Glacier Surges ◽  
Fast Motion

AbstractMany glaciers in Svalbard and in other glacierized areas of the world are known to surge. However, the time series of observations required to assess the duration of fast motion is very restricted. Data on active-phase duration in Svalbard come from aerial photographs, satellite imagery, field surveys and airborne reconnaissance. Evidence on surge duration is available for eight Svalbard ice masses varying from 3 to 1250 km2. Worldwide, active-phase duration is recorded for less than 50 glaciers. Few observations are available on high polar ice masses. The duration of the active phase is significantly longer for Svalbard glaciers than for surge-type glaciers in other areas from which data are available. In Svalbard, the active phase may last from 3 to 10 years. By contrast, a surge duration of 1–2 years is more typical of ice masses in northwest North America, Iceland and the Pamirs. Ice velocities during the protracted active phase on Svalbard glaciers are considerably lower than those for many surge-type glaciers in these other regions. Mass is transferred down-glacier more slowly but over a considerably longer period. Svalbard surge-type glaciers do not exhibit the very abrupt termination of the active phase, over periods of a few days, observed for several Alaskan glaciers. The duration of the active phase in Svalbard is not dependent on parameters related to glacier size. The quiescent phase is also relatively long (50–500 years) for Svalbard ice masses. Detailed field monitoring of changing basal conditions through the surge cycle is required from surge-type glaciers in Svalbard in order to explain the significantly longer length of the active phase for glaciers in the archipelago, which may also typify other high polar ice masses. The finding that surge behaviour, in the form of active-phase duration, shows systematic differences between different regions and their environments has important implications for understanding the processes responsible for glacier surges.

scholarly journals Refining Estimates of Polar Ice Volumes during the MIS11 Interglacial Using Sea Level Records from South Africa

2014 ◽  
Vol 27 (23) ◽  
pp. 8740-8746 ◽  
Author(s):  
Florence Chen ◽  
Sarah Friedman ◽  
Charles G. Gertler ◽  
James Looney ◽  
Nizhoni O’Connell ◽  
...  
Keyword(s):  
South Africa ◽  
Sea Level Rise ◽  
Sea Level ◽  
Ice Sheet ◽  
Sea Level Change ◽  
Polar Ice ◽  
Level Change ◽  
Isostatic Adjustment ◽  
West Antarctic ◽  
Numerical Predictions

Abstract Peak eustatic sea level (ESL), or minimum ice volume, during the protracted marine isotope stage 11 (MIS11) interglacial at ~420 ka remains a matter of contention. A recent study of high-stand markers of MIS11 age from the tectonically stable southern coast of South Africa estimated a peak ESL of 13 m. The present study refines this estimate by taking into account both the uncertainty in the correction for glacial isostatic adjustment (GIA) and the geographic variability of sea level change following polar ice sheet collapse. In regard to the latter, the authors demonstrate, using gravitationally self-consistent numerical predictions of postglacial sea level change, that rapid melting from any of the three major polar ice sheets (West Antarctic, Greenland, or East Antarctic) will lead to a local sea level rise in southern South Africa that is 15%–20% higher than the eustatic sea level rise associated with the ice sheet collapse. Taking this amplification and a range of possible GIA corrections into account and assuming that the tectonic correction applied in the earlier study is correct, the authors revise downward the estimate of peak ESL during MIS11 to 8–11.5 m.

Nitrate abundance in polar ice during the great solar activity minimum

2002 ◽  
Vol 29 (11) ◽  
pp. 1707-1711 ◽  
Author(s):  
O.G. Gladysheva ◽  
G.E. Kocharov ◽  
G.A. Kovaltsov ◽  
I.G. Usoskin
Keyword(s):  
Solar Activity ◽  
Polar Ice ◽  
Solar Activity Minimum
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