Transcripts of Sea_ice_interlude



[music] Welcome to an Operation IceBridge sea ice interlude. 

[music] We start with a visualization of AMSR-E data from the Aqua satellite, showing sea ice, or frozen seawater, pulsing over the course of months around the Antarctic continent.IceBridge often passes around the Antarctic continent.IceBridge often passes passes the scenic Antarctic Peninsula on its way to survey the continent’s ice sheets, glaciers, Usually the peninsula's mountains are shrouded by clouds but today we have a clear view. As we descend, we see vast fields of sea ice, which comes in an array of shapes and thicknesses. Large pieces of sea ice are called floes and these formations often collide, creating thick ridges along their edges, or raft over top of each other. This ice appears to be thick enough to be 2nd-year ice, or ice which survived a summer melt season. Darker, grayer ice appears to be more recent, and might be around 10 cm thick, while the white ice covered by snow is probably more than 30 cm thick. The area in the lower center here is so smooth,  it might just be a few hours old. This is frazil ice. It’s granular, like a slushy beverage, and is created by very dynamic conditions of turbulence in the water. This is a region of brush, containing sea ice and a few icebergs. IceBridge measures Antarctic ice from 500 meters above the surface, using radar, laser altimetry, and with these crisp images from the DMS or Digital Mapping System. Here we have ice that’s holding fast to the shore, and immobilizing icebergs from a nearby glacier or ice shelf. These slabs of ice from continental ice shelves, sticking above the water by perhaps 50 meters are large and flat enough to be called tabular bergs.  Finally, the slowly setting sun lights up cracks or leads in the sea ice as we head for home.