The West Antarctic Ice Sheet: Instability, disintegration, and initiation of Ice Ages

摘要: An ice age model is proposed in which glacial-interglacial global climatic cycles are controlled by interactions between the cryosphere, hydrosphere, and atmosphere Atlantic environment. In model, change results from instabilities develop snowfields or sheets of North America, Europe, Antarctica. Disintegration West Antarctic sheet (that portion lying western hemisphere) initiates a chain events culminates age. Ten independent bodies data can be interpreted as evidence that has been disintegrating. The dynamics Ross Sea drainage system Antarctica examined to determine what controls disintegration recovery sheet. It concluded streams drain inherently unstable outlet glaciers stable East Glacial stability both cases determined degree coupling its bed. Ice channels when this weakened normal margin an lead surges glaciers. shelves parallel rapid grounding line retreat floating tongues shelves. inflection maximum on surface migrates inland during surge seaward after spent. A transition zone shelf widens narrows advance seaward. Inflection migrations combine give concave convex advance. train surging segments stream lowers stages, creating terraced causes discontinuous retreats line. Rapid glacial following truncate advancing sheet-ice boundary. Today at least one glacier truncated system. If condition general, disintegrating along Siple Coast result recovering Transantarctic Mountains thickening competition these processes will provide critical test predicts progressive growth adjacent parts