Showing posts with label subglacial lakes. Show all posts
Showing posts with label subglacial lakes. Show all posts

Monday, November 09, 2015

Does the Circular Collapsed Terrain in the Martian Chryse Region Come From Subglacial Lakes?

Origin of circular collapsed landforms in the Chryse region of Mars

Authors:


Roda et al

Abstract:


The quasi-circular collapsed landforms occurring in the Chryse region of Mars share similar morphological characteristics, such as depth of collapse and polygonally fractured floors. Here, we present a statistical analysis of diameter, maximum and minimum depth, and amount of collapse of these features. Based on their morphometric characteristics, we find that these landforms have a common origin. In particular, the investigated landforms show diameter-depth correlations similar to those that impact craters of equivalent diameters exhibit. We also find that the observed amount of collapse of the collected features is strongly correlated to their diameter. Furthermore, the linear relation between minimum filling and pristine depth of craters, the constant ratio between collapse and the amount of filling and the fractured and chaotic aspect of the filling agree with melting and subsequent collapse of an ice layer below a sediment layer. This interpretation is consistent with a buried sub-ice lake scenario, which is a non-climatic mechanism for producing and storing abundant liquid water under martian conditions.

Wednesday, January 28, 2015

Craters From Two Subglacial Lakes Found in Greenland


Researchers who are building the highest-resolution map of the Greenland Ice Sheet to date have made a surprising discovery: two lakes of meltwater that pooled beneath the ice and rapidly drained away.

One lake once held billions of gallons of water and emptied to form a mile-wide crater in just a few weeks. The other lake has filled and emptied twice in the last two years.