Tag Archives: #rising sea

Antarctic Shiver

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Everyone knows the best scare stories are those in which the most obvious and visible danger turns out to less dire than an unsuspected peril revealed only later, the deadfall that sends a shiver down the listener’s spine.

We’ve all heard about the Antarctic ice shelf melt-off that’s been taking place with increasing speed and frequency. But at least there was always a comforting swathe of East Antarctica, the thick part that wasn’t floating like a massive ice cube in a warming drink.

The Totten Glacier catchment basin (blue outline) is three-quarters the size of Texas and holds the ice and snow that flows through the glacier. Credit: Australian Antarctic Division via LiveScience

The Totten Glacier catchment basin (blue outline) is three-quarters the size
of Texas and holds the ice and snow that flows through the glacier.
Credit: Australian Antarctic Division via LiveScience

As it turns out, what lies beneath a large part of East Antarctica is not, as previously thought, solid earth. Rather, it appears that there might be water flowing through large subsea troughs, regions of the seabed that slope away from the ice above, allowing warmer water to melt the largest ice sheet in the world from below.

Most research to date has focused on West Antarctica. An international team of scientists carried out the study, published in Nature Geoscience, to investigate why satellite images seemed to show that the Totten Glacier was growing thinner.

Carrying out measurements by plane flyovers, the resulting cartography indicated the presence of invisible valleys and warm water carried there by heavy salt concentrations.

The aircraft that researchers flew over East Antarctica to map Totten Glacier. Credit: Chad Greene via LiveScience

The aircraft that researchers flew over East Antarctica to map Totten Glacier.
Credit: Chad Greene via LiveScience

The ice is 480 m (1600 ft) thick in some places. To get to the bottom of the ice from the height of a plane, three methods were used: gravitational measurements, radar and laser altimetry.

The radar was used to measure the thickness of the ice. Gravitational pull on the plane was measured at various points to determine the location of the seafloor beneath the ice.

The next step will be to send down underwater to verify initial study results and monitor activity of Circumpoloar Deep Water at the base of the glacier.

Actually, like turning on all the lights after the end of a good scary story, the next step for me will be to remind myself that if and when the sea rises to Pliocene Epoch levels, we might have had time to develop more effective ways of living with a lot of water in places where there is now land.

I also recommend a visit this other, more benign exploration into how ice behaves, the Icicle Atlas. I think the images of icicles forming look a bit like shivers running down a spine:

 

A clip from the wonderful Icicle Atlas, a creation of Stephen Morris at the Physics Department at the University of Toronto that explores how icicles form. A visit to the Rogue's Gallery of icicles is a mesmerizing and informative trip. Source: Icicle Atlas/Univ. of Toronto

A clip from the wonderful Icicle Atlas, a creation of Stephen Morris at the Physics Department at the University of Toronto that explores how icicles form. A visit to the Rogue’s Gallery of icicles is a mesmerizing and informative trip.
Source: Icicle Atlas/Univ. of Toronto

Reaching New Shores

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Circular plot of migration flows of at least 170,000 people between and within world regions during 2005 to 2010. Tick marks show the number of migrants (inflows and outflows) in millions.  Click to enlarge.  Image courtesy of Abel et al., Science/AAAS via Co.Exist

Circular plot of migration flows of at least 170,000 people between and within world regions during 2005 to 2010. Tick marks show the number of migrants (inflows and outflows) in millions.
Image: Abel et al., Science/AAAS via Co.Exist

The Intergovernmental Panel on Climate Change (IPCC) recently released a report on the development of climate change and its effects on humans.

The 2600-page report is the result of three years work and the collaboration of 300 scientists.

It makes for mostly grim reading, with an emphasis on climate impact on food security (not positive), on extreme weather events (increasing), and on poverty (again, not positive).

The global migration patterns in the interactive graphic above illustrate twenty years of migration statistics from 196 countries. Created by the Wittgenstein Centre for Demography and Human Capital in Vienna, the graphic uses software lifted from the field of genetic research.

It’s interesting to note that the number of people who actually leave their country of birth for good has remained at more or less the same level across decades – a mere 0.6% of the population. As a long-term expat among many long-term expats, it often seems like the number must be much higher, but such is the power of subjective perception. What we think we see up close isn’t always what’s happening if seen at a distance.

Quoted in Co.Exist, the authors say, “These long-distance flows are effective at redistributing population to countries with higher income levels, whereas return flows are negligible.” So, migration has been for mainly economic reasons, or for reasons of security offered in higher-income countries.

Given the IPCC report and its sobering conclusions regarding food security and extreme weather events, I wonder how these migration patterns and numbers will develop over the next few decades – which areas will see more migration inflow. The higher ground countries as well as those with higher-income?

Will we as humans follow many animals, flee an ever-warmer planetary midsection, and migrate north?

And what about that migration number of people who permanently leave their home country, 0.6%, that’s been steady for so long? Should climate change redraw the coastlines of continents and the boundaries of nations, what will count as ‘migration’ and what will count as keeping one’s head above water?

The World - Rising Sea Level, first map of its kind on such a scale and level of complexity, depicts our planet as it would look without its polar ice caps, with sea levels 260 ft higher as they are today. Click map for a larger version. Artist: Jay Simons

The World – Rising Sea Level, first map of its kind on such a scale and level of complexity, depicts our planet as it would look without its polar ice caps, with sea levels 260 ft higher as they are today. This detailed map can be viewed in all its glorious cartographic futurism by clicking on the map or following the link of the artist, Jay Simons.
Click map for a larger version.
Artist: Jay Simons