Articles Flashcards
What singular event could raise sea levels by half a metre.
A major glacier in Greenland that holds enough water to raise global sea levels by half a metre has begun to crumble into the North Atlantic Ocean, scientists say.
What is the Greenland glacier called?
Zachariae Isstrom
When did Zachariae Isstrom begin to melt rapidly?
The huge Zachariae Isstrom glacier in northeast Greenland started to melt rapidly in 2012 and is now breaking up into large icebergs where the glacier meets the sea, monitoring has revealed.
How fast is the Zachariae Isstrom glacier retreating?
The enormous Zachariae Isstrom glacier began to recede three times faster from 2012, with its retreat speeding up by 125 metres per year every year until the most recent measurements in 2015.
How much has the Zachariae Isstrom glaciers floating shelf decreased?
From 2002 to 2014 the area of the glacier’s floating shelf shrank by a massive 95%, according to a report in the journal Science.
What weight has the Zachariae Isstrom lost each year?
The glacier has now become detached from a stabilising sill and is losing ice at a rate of 4.5bn tonnes a year.
What is causing the Zachariae Isstrom galcier to melt?
rising air temperatures driving melting at the top of the glacier, and its underside being eroded away by ocean currents that are warmer now than in the past.
What glacier in Greenland is similar to the to the north of Zachariae Isstrom?
To the north of Zachariae Isstrom, the scientists studied a second large glacier called Nioghalvfjerdsfjorden.
What change would the melting of both the Zachariae Isstrom and the Nioghalvfjerdsfjorden glacier cause?
Together, the two glaciers drain a region of nearly 200,000 sq km, amounting to 12% of the Greenland ice sheet. Were both to melt, they would contribute a full metre to global sea levels.
How much have sea levels risen over the past century?
Core samples, tide gauge readings, and, most recently, satellite measurements tell us that over the past century, the Global Mean Sea Level (GMSL) has risen by 4 to 8 inches (10 to 20 centimeters).
What is the annual sea level rise over the last 20 years compared to the last century?
However, the annual rate of rise over the past 20 years has been 0.13 inches (3.2 millimeters) a year, roughly twice the average speed of the preceding 80 years.
Greenhouse gas emissions have caused the Earth’s surface temperature to rise, where is this heat going?
The oceans absorb about 80 percent of this additional heat.
The rise in sea levels is linked to three primary factors, all induced by this ongoing global climate change: describe thermal expansion.
Thermal expansion: When water heats up, it expands. About half of the past century’s rise in sea level is attributable to warmer oceans simply occupying more space.
The rise in sea levels is linked to three primary factors, all induced by this ongoing global climate change: describe melting of glaciers and polar ice caps?
Melting of glaciers and polar ice caps: Large ice formations, like glaciers and the polar ice caps, naturally melt back a bit each summer. But in the winter, snows, made primarily from evaporated seawater, are generally sufficient to balance out the melting. Recently, though, persistently higher temperatures caused by global warming have led to greater-than-average summer melting as well as diminished snowfall due to later winters and earlier springs. This imbalance results in a significant net gain in runoff versus evaporation for the ocean, causing sea levels to rise.
The rise in sea levels is linked to three primary factors, all induced by this ongoing global climate change: describe the final factor - not thermal expansion or the melting of glaciers and polar ice caps.
As with glaciers and the ice caps, increased heat is causing the massive ice sheets that cover Greenland and Antarctica to melt at an accelerated pace. Scientists also believe meltwater from above and seawater from below is seeping beneath Greenland’s and West Antarctica’s ice sheets, effectively lubricating ice streams and causing them to move more quickly into the sea. Moreover, higher sea temperatures are causing the massive ice shelves that extend out from Antarctica to melt from below, weaken, and break off.
Describe an environmental consequence of rising sea levels.
As seawater reaches farther inland, it can cause destructive erosion, flooding of wetlands, contamination of aquifers and agricultural soils, and lost habitat for fish, birds, and plants.
How high can we expect sea levels to rise?
A recent study says we can expect the oceans to rise between 2.5 and 6.5 feet (0.8 and 2 meters) by 2100, enough to swamp many of the cities along the U.S. East Coast. More dire estimates, including a complete meltdown of the Greenland ice sheet, push sea level rise to 23 feet (7 meters), enough to submerge London.
Name two places in America that will be severely affected by rising sea levels have have already been hit by Hurricane Sandy.
Fort Lauderdale and New York
Where did hurricane sandy hit?
Before Hurricane Sandy tore through New York and New Jersey, it stopped in Florida. Huge waves covered beaches, swept over Fort Lauderdale’s concrete sea wall and spilled onto A1A, Florida’s coastal highway.
What did beach erosion at Fort Lauderdale cause?
Beach erosion forced Fort Lauderdale to buy sand from an inland mine in central Florid.
How is climate change affecting hurricanes?
As the oceans warm, hurricanes are growing more intense.
What is making storms in America so economically devastating?
Americans have rushed to build homes near the beach. Storms that lash the modern American coastline cause more economic damage than their predecessors because there is more to destroy.
Compare a storm hitting America now to one that hit in the past.
he Great Miami Hurricane of 1926, a Category 4 storm, caused $1 billion-worth of damage in current dollars. Were it to strike today the insured losses would be $125 billion, reckons AIR Worldwide, a catastrophe-modelling firm.
What makes Storms so devastating for Floridians?
Most Floridians live in coastal counties. Buildings cluster on low ground; more people than in any other state live on land less than four feet (1.2 metres) above the high-tide line. Florida’s limestone bedrock makes it easy for salt water from surging seas to contaminate its freshwater aquifers. And it relies heavily on canals for flood control, which a sea-level rise of just six inches would devastate.