Danish officials today announced promising initial results of a project using satellites to collect cartographic data faster and more efficiently than has been possible using aeroplanes.
The project involved using SPOT 6 and 7, two commercially operated European satellites, flying at an altitude of 700km to collect images of four specific areas […]. The pictures they returned over a two-year period beginning in 2015 each measure 360 square km. Objects as small as 1.5 m can be discerned in the pictures, making them detailed enough to be used to make precise, high-resolution maps.
Cartographers are now in the process of turning the data into finished, on-line maps. The maps themselves are expected to publicly available by autumn. But, even before that, the data gathered by the satellites will be placed on-line.
At All Over the Map, Betsy Mason posts 11 Ways to See How Climate Change Is Imperilling the Arctic, a collection of maps and infographics depicting several different indicators of global warming, including sea ice extent, atmospheric temperatures, growing season, polar bear populations, as well as projected shipping routes for an ice-free Arctic Ocean.
Meanwhile, NASA Earth Observatory points—while it still can—to a study mapping the extent of existing and potential thermokarst (thawed permafrost) landscapes. On the Earth Observatory maps (see North America, above), “[t]he different colors reflect the types of landscapes—wetlands, lakes, hillslopes, etc.—where thermokarst is likely to be found today and where it is most likely to form in the future.”
NASA Earth Observatory: “In November, the sea ice extent averaged 9.08 million square kilometers (3.52 million square miles)—the lowest November extent in the satellite record. The yellow line shows the median extent from 1981 to 2010, and gives an idea of how conditions this November strayed from the norm.” Also shows sea ice extent for previous years dating back to 1978. Hudson Bay was icebound in November not that long ago.
Something’s going on in the Arctic. As the Washington Post reported last month, the Arctic Ocean was far, far warmer than normal—about 20 degrees Celsius higher than average. (Meanwhile, the air over Sibera is at record cold levels.) According to the Post, the higher temperatures are the result of record low amounts of thinning sea ice, as well as warm air being brought north by an increasingly errant jet stream.
NASA has been tracking sea ice levels and thickness by looking at the age of the ice in the sea ice cap. The video above shows “how Arctic sea ice has been growing and shrinking, spinning, melting in place, and drifting out of the Arctic for the past three decades. The age of the ice is represented in shades of blue-gray to white, with the brightest whites representing the oldest ice.”
The ESA reports that their CryoSat satellite “has found that the Arctic has one of the lowest volumes of sea ice of any November, matching record lows in 2011 and 2012.” The animated GIF below shows the change in November sea ice from 2011 to 2016, as observed by CryoSat.
Most maps published by the Canadian government, including the poster-sized map I have on my wall, claim a vast tract of the Arctic Ocean, all the way up to the North Pole—basically everything east of 141 degrees west longitude—as Canadian territory. The National Post’s Tristin Hopper argues that this is a mistake. Canada doesn’t even officially claim that (briskly melting) expanse of ice.
The incorrect Canadian maps are all based on the old-fashioned “sector theory” of claiming the Arctic. Back when the Arctic Ocean was largely an inaccessible chunk of ice that swallowed explorers, polar nations were generally content with dividing it up like the slices of a pizza that had the North Pole at its centre. […]
Nevertheless, while various expansionist Canadian politicians have enthusiastically touted some version of the sector theory over the years, it has never been officially adopted as Canadian policy.
A new digital elevation model of Alaska was released earlier this month. The result of a presidential directive to improve elevation maps of Alaska as a tool “to help to help communities understand and manage” the risks of climate change, the ArcticDEM project is a collaboration between the National Geospatial-Intelligence Agency (NGA), the National Science Foundation (NSF) and the University of Minnesota, among others. The unclassified data gives two-metre (or better) resolution across the state. Lower-resolution DEMs for the entire Arctic will follow next year.
Digital elevation data for Alaska had previously been poor; the National Geographic article leads with the point that Mars has better topographic maps than Alaska does. Most digital elevation data is collected by airplane—an impractical method in the far north; the ArcticDEM is based on stereo imagery from DigitalGlobe satellites. (As a comparison, the Shuttle Radar Topography Mission’s DEM resolution is 30 metres for the U.S., 90 metres elsewhere.)
CBC News reports on the Canadian Coast Guard’s project to map the continental shelf under the Arctic Ocean, now in its third and final year. This is part of Canada’s attempt to stake a claim to the continental shelf (and seas above it) beyond the 200-mile nautical limit, which other Arctic countries (hello, Russia) are also trying to do.
Climate change has made the Arctic increasingly open to shipping, and more ships travel the Canadian Arctic every year. But as Claire Eamer argues in Hakai magazine, the lack of mapping makes such voyages a dangerous proposition. “[J]ust because the ice is melting it doesn’t mean the waterways are safe. The federal Canadian Hydrographic Service (CHS) is responsible for mapping Canada’s waters. So far, they’ve only managed to map roughly 10 percent of Arctic waterways in accordance with international standards.” [CCA]
NASA Earth Observatory: “The map above, based on data provided by the National Snow and Ice Data Center, shows the extent of Arctic permafrost. Any rock or soil remaining at or below 0 degrees Celsius (32 degrees Fahrenheit) for two or more years is considered permafrost.” The map differentiates between continuous, discontinuous, sporadic and isolated permafrost. [NASA Earth]