Antarctica is known to be geothermically active. "A new NASA study adds evidence that a geothermal heat source called a mantle plume lies deep below Antarctica's Marie Byrd Land, explaining some of the melting that creates lakes and rivers under the ice sheet. Although the heat source isn't a new or increasing threat to the West Antarctic ice sheet, it may help explain why the ice sheet collapsed rapidly in an earlier era of rapid climate change, and why it is so unstable today. The stability of an ice sheet is closely related to how much water lubricates it from below, allowing glaciers to slide more easily. Understanding the sources and future of the meltwater under West Antarctica is important for estimating the rate at which ice may be lost to the ocean in the future. Antarctica's bedrock is laced with rivers and lakes, the largest of which is the size of Lake Erie." This map shows the continent's subglacial rivers and lakes. www.jpl.nasa.gov/news/news.php?feature=6996
Antarctica is our most challenging continent to study, but what's going on there (or isn't) is pivotal to accurate estimates of sea level rise, which in turn are pivotal to the tens of millions of people living within a few meters of sea level. This TED Talk discusses how researchers are using radar and radio to peer through 3 km of ice to better understand how Antarctica may be changing.
Welcome to the North Pole! This planar map provides a different perspective on the Arctic than a customary equator-centered map does. As the Arctic is heating up, literally, Arctic politics are also heating up, with conflict over shipping lanes, fishing rights, mineral rights, and militarization emerging between the eight countries bordering the Arctic Ocean as well as with indigenous peoples (including elves?). www.wolfram.com/mathematica/new-in-10/geographic-visualization/HTMLImages.en/map-the-north-pole-and-arctic-circle/O_11.png
It has long been known Antarctica is volcanic: Mt. Erebus is the world's southernmost active volcano and has been erupting continuously for decades. Geologists recently found 91 new volcanoes under Antarctica's ice sheets. These volcanoes, currently dormant, are clustered in Marie Byrd Land, the portion of Antarctica directly south of New Zealand. www.sci-news.com/featurednews/volcanoes-west-antarctica-05129.html
The International Ice Patrol, created after the sinking of the Titanic to monitor icebergs in the North Atlantic, has recorded 976 icebergs off Newfoundland so far this year, more than double the average. The icebergs drift into shipping lanes (generally south of 48◦ north latitude) and pose a threat to trans-Atlantic maritime traffic. This article from The Economist notes that number of icebergs varies considerably from year to year, depending on a variety of physical geography cues, including water and air temperature, ocean currents, and wind strength. www.economist.com/blogs/economist-explains/2017/06/economist-explains-14
If you want to learn more about Antarctica, this is your chance. EdX is offering a new (free) class, "Antarctica: From Geology to Human History," that takes participants on "a virtual field trip to Antarctica, as we go on location to explore the geology and history of the coldest, driest, windiest continent on earth." The class starts, online, tomorrow (4/15) and runs for five weeks. www.edx.org/course/antarctica-geology-human-history-victoriax-ice101x
A banana plantation 177 miles south of the Arctic Circle? Yes. Iceland takes advantage of its geothermal position on the Mid-Atlantic Ridge to grow bananas (in a greenhouse heated by volcanic hot springs). Geothermal sources provide 66% of Iceland's energy, including direct heating and 25% of its electricity generation. www.atlasobscura.com/articles/bananas-in-iceland
Last week it was reported that the sea ice surrounding Antarctica reached the lowest level in recorded history in January. In the Arctic, where it is winter, sea ice also set a new record low for January. This article from National Geographic asks, "What would the world look like if all of the planet's ice melted?" Check out the before-and-after map for each continent. www.nationalgeographic.com/magazine/2013/09/rising-seas-ice-melt-new-shoreline-maps/
Permafrost turns out to not be quite as "perma" as Soviet planners thought. When the Soviet Union threw up new cities in Siberia to support the extraction of various natural resources there, infrastructure and buildings, including multistory apartment buildings, were constructed on top of the permafrost. Now, as the permafrost has begun to melt and shift, the structural integrity of these cities is at risk. A new study looks at engineering threats to Siberia's cities: onlinelibrary.wiley.com/doi/10.1111/gere.12214/full Permafrost underlies as much as 2/3 of Russia's landmass.
It's the beginning of summer in Antarctica, and scientists have announced that a section of Antarctica's ice shelf the size of Delaware is likely to break off this season. The Larsen C ice shelf is Antarctica's 4th largest and sits atop the Weddell Sea, near the end of the peninsula that points towards the tip of South America. If the 5,000 square km chunk of Larsen C does break off, it will create one of the largest icebergs ever recorded. This photo is an aerial view of the crack, which abruptly fissured an additional 18 km last month. www.washingtonpost.com/news/energy-environment/wp/2017/01/06/the-crack-in-this-antarctic-ice-shelf-just-grew-by-11-miles-a-break-could-be-imminent/?utm_term=.75c594cdfbfa
The Arctic Circle passes through eight countries* and is the northernmost of the five major circles of latitude (e.g., Equator, Tropic of Capricorn). The precise location of the Arctic Circle varies with the tilt of the earth on its axis but is defined as the southernmost location from which the sun is still visible at midnight at least once a year and from which the sun is not visible at noon at least once a year. This geography imposes unusual conditions, beyond the cold, for life above the Arctic Circle. This article details some of the surprising adaptations of the reindeer (or caribou) to its extreme geography: www.bbc.com/earth/story/20151209-why-reindeer-noses-are-more-amazing-than-you-think
*Can you name all eight countries without looking at a map?
[answers: Russia, Canada, the U.S. (in Alaska), Denmark (in Greenland), Iceland (in territorial islands), Norway, Sweden, and Finland]
This series of maps shows changes in minimum annual sea ice at the poles between 1980 and 2016. (The darker blue is sea ice; the lighter blue is where sea ice used to be.) The presence or absence of sea ice has a significant impact on biogeography as well as on local and global physical geography: sea ice reflects 80% of the sunlight that hits it, whereas open water reflects only 10% of the sunlight that hits it, absorbing (and being heated by) the other 90%. www.economist.com/blogs/graphicdetail/2016/11/daily-chart-14
Blog sharing news about geography, philosophy, world affairs, and outside-the-box learning
This blog also appears on Facebook: