Lecture 14: Ice Flashcards
How has sea ice extent changed (grown, remained stable, declined?) over the last
few decades in the Arctic and Antarctic?
Arctic: Sea ice extent has declined significantly.
Antarctic: Sea ice extent has shown regional variability, but the overall trend is decline.
How has sea ice extent changed (grown, remained stable, declined?) over the last
few (three to four) years in the Arctic and Antarctic?
Arctic: Sea ice extent has continued to decline in recent years.
Antarctic: Sea ice extent has shown fluctuating trends, with some regions experiencing decline.
What is the “doomsday” glacier
The Thwaites Glacier in Antarctica is often referred to as the “doomsday” glacier due to its potential to significantly raise sea levels if it collapses.
Approximately how many solid H2O phases are there?
There are over 10 known solid phases of water (H2O).
What are the fastest ice velocities of the Antarctic and Greenland ice sheets?
Antarctic: The fastest velocities are around 1,000 meters per year in the Ross Ice Shelf.
Greenland: The fastest velocities are around 1,500 meters per year in certain regions.
What is the pattern of ice velocity in the Antarctic and Greenland ice sheets?
In both regions, ice velocity is faster near the coast and slower inland due to gravitational flow and bedrock variations.
How thick is the ice in East Antarctica and West Antarctica?
East Antarctica: Ice thickness reaches up to 4,800 meters.
West Antarctica: Ice thickness ranges from 1,000 to 2,500 meters.
How old is the oldest ice recovered in deep ice cores?
The oldest ice cores recovered are about 800,000 years old.
What is the name of the New Zealand led palaeo-climate ice core project?
The project is called the ANDRILL (Antarctic Drilling) project
When were atmospheric CO2 levels last at concentrations equivalent to today and what was the sea level relative to today?
Atmospheric CO2 levels were last at current concentrations (~400 ppm) about 3 million years ago, when sea levels were approximately 15-25 meters higher than today.
How much is sea level predicted to rise if all the ice in Antarctica were to move onto the ocean?
If all the ice in Antarctica melted, sea level would rise by approximately 58 meters.
Which areas of New Zealand have the fastest rates of sea level rise?
South Island’s west coast and the North Island have the fastest rates of sea level rise.
What is the approximate ratio of ice shelf thickness and the elevation (height above sea level) of the surface of that ice shelf?
Typically, the thickness of an ice shelf is about 10 times the elevation (height above sea level) of the ice shelf surface.
