Ice streams are corridors of quick flow within an ice sheet (possibly 800 meters annually).They discharge a lot of ice and sediment from various ice sheets, flowing orders of magnitude quicker than their surrounding ice. Their stability and behaviors are paramount to the entire ice sheet dynamics and even the mass balance. Currently, the Antarctic Ice Sheet discharges nearly 90% of ice and sediment through the ice stream. Antarctic Stream Ice are naturally fed by complex tributaries which extend about 100km into the interior of the ice sheet.
Ice streams are usually huge features with a convergent onset zone feeding into a major channel. Modern ice streams are normally associated with pervasively offshore trough-mouth fans and deformed till, depocentres for the huge volumes of sediment which are transported from the interior of the ice sheet towards to the continental shelves.
Ice streams can also be constrained by areas of slow moving ice or by topography. They are known as pure ice streams or topographic ice streams respectively. Both kinds show variations in behavior (both through space and time) that indicates potential for instability and are therefore specifically interesting. Their discharge of ice into the ocean basins affects thermal and saline ocean circulation. Ice streams have therefore been a top focus for research worldwide for the last 30 years.
Some ice streams occur due to a combination of topographic and pure, bounded by both topography and ice. There is perfect evidence that soft deformable sediments are a real pre-requisite for quick ice flow; sub-glacial geology, therefore, is crucial in defining ice stream location.
Interesting Facts Ice Streams:
- The ice stream is typically great features (more than 20km wide, greater than 150km in length), with a convergent onset zone only feeding the main channel.
- Ice streams can depend on the topography or by places of slow-moving ice. They are known as topographic ice streams or rather pure ice streams respectively.
- Ice streams can develop in areas with weaker ice or have a lubricated bed to support the basal motion.
- Some ice stream is as a result of topography and entirely bonded by both topography and ice itself.
- Ice stream reduces surface topography, with more ice sheet drawn down for pure stream ice that tends to have more ice flow volumes.
- The pure ice stream is likely to change through space and time, switching on and off and shifting location.
- The thickness, flow velocity and grounding lines of ice streams are always changing over decadal timescales.In fact, the observations in Antarctica of acceleration, thinning, deceleration, stagnation, and even lateral migration.
- The flow velocity, thickness and grounding lines of ice streams are variable over different decadal timescales, with observations in Antarctica of thinning, acceleration, deceleration, stagnation and lateral migration
- Ice streams around the Siple Coast in West Antarctica discharges almost 40% of the ice from the whole West Antarctica Ice West.