Radiocarbon dating easy explanation
ICEsat satellite observations of subglacial lakes has shown that the ice surface above subglacial lakes is constantly changing, suggesting that water is flowing between lakes[5,8].
These lakes, identified in regions of ice-stream onset zones, and characterised by changes in elevation, are considered active, whilst the lakes identified by RES under thicker ice under Dome C, for example, are considered inactive.
This radio wave is then received by the aeroplane, and yields ice-thickness data to within 1.5% accuracy.
This lake has between 37 m of ice above it[4, 7], and is 14,000 km in area.The location of subglacial lakes is important, because the presence of meltwater and saturated subglacial sediments facilitates rapid ice velocity (see Ice streams).Water-saturated sediments reduce basal shear stress, allowing basal sliding at low driving stresses[6, 9].It lies within a subglacial topographic basin, similar to a rift valley.It is at least 1000 m deep in the south, but relatively shallow in its northern and southwest corners. NASA’s repeat-track uses laser altimeter data to measure height changes at a high resolution.