Landsat observations have charted the erosion of the banks of the ever-changing Padma River, a major distributary of the Ganges in Bangladesh. This is vividly shown in this animation produced by NASA Earth Observatory, which “shows 14 false-color images of the Padma river between 1988 and 2018 taken by the Landsat 5 and 8 satellites. All of the images include a combination of shortwave infrared, near infrared, and visible light to highlight differences between land and water.” More on the erosion of the Padma River here.
Hey look, GIS people: Randall Munroe made an xkcd comic just for you.
Because of its thick and opaque atmosphere, Titan had to be mapped in radar and infrared during a series of close flybys by the Cassini spacecraft. One artifact of this process: the resolution, lighting and atmospheric conditions were not consistent, so mosaic images and maps of Titan’s surface showed visible seams. That’s been corrected in these infrared images of Titan’s surface, released last week. The false-colour images remap infrared wavelengths to the visible spectrum, using a band-ratio technique that minimizes seams. “With the seams now gone, this new collection of images is by far the best representation of how the globe of Titan might appear to the casual observer if it weren’t for the moon’s hazy atmosphere, and it likely will not be superseded for some time to come.”
Previously: Mapping Titan with VIMS.
This is a map of the United States without insets. Published in 1975 by the U.S. Geological Survey, it shows Alaska, Hawaii and the lower 48 states in the same, continuous view—though Hawaii’s Leeward Islands are cut off (as are the various territories). Can’t have everything, I guess. It’s available from the USGS as a free downloadable PDF; the paper version costs $9. [MapPorn]
Previously: Alaska’s Cartographic Revenge.
We’ve seen maps reimagining the United States reorganized into a different number and configuration of states before, but this map by Reddit user Upvoteanthology_ looks north of the border for inspiration. It imagines what would happen if the U.S. were organized like Canada, with the same population imbalances: Ontario, for example, has 38.9 percent of the Canadian population, so this map imagines a superstate, Shanherria, with 38.9 percent of the U.S. population that spans the entire U.S. South, plus Kentucky, Missouri, Kansas and the non-Chicago parts of Illinois. Meanwhile, Maine is roughly equivalent to Prince Edward Island, and the three northern territories map to Alaska.
Cape Town is running out of drinking water, a crisis dramatically depicted by NASA Earth Observatory maps that show the depletion of the city’s reservoirs. The animated gif above, for example, “shows how dramatically Theewaterskloof [Cape Town’s largest reservoir] has been depleted between January 2014 and January 2018. The extent of the reservoir is shown with blue; non-water areas have been masked with gray in order to make it easier to distinguish how the reservoir has changed. Theewaterskloof was near full capacity in 2014. During the preceding year, the weather station at Cape Town airport tallied 682 millimeters (27 inches) of rain (515 mm is normal), making it one of the wettest years in decades. However, rains faltered in 2015, with just 325 mm falling. The next year, with 221 mm, was even worse. In 2017, the station recorded just 157 mm of rain.”
The maps that appear from time to time on xkcd are usually a lot more whimsical than the one Randall posted today: his somewhat belated “2016 Election Map” assigns one figure for every 250,000 votes for each of the 2016 presidential election candidates. As Randall says in the alt text,1 “I like the idea of cartograms (distorted population maps), but I feel like in practice they often end up being the worst of both worlds—not great for showing geography OR counting people. And on top of that, they have all the problems of a chloro… chorophl… chloropet… map with areas colored in.” This is an issue that election map cartographers regularly have to deal with, as many of my readers know well.
I didn’t know Replogle made Christmas ornaments. I stumbled across the above, a Waldseemüller globe ornament—i.e., an ornament based on the Waldseemüller globe gores—while poking around my local map store for the first time in years. I bought the last one they had in stock. It’s 3¼″ (8.3 cm) in diameter, comes with a stand, and cost me all of $10. There’s apparently a Coronelli globe ornament as well.
Cartographers in the Field: “This Depression-era oil painting was created by USGS field man Hal Shelton in 1940. The painting depicts mapping techniques used in the early days of cartography, including an alidade and stadia rod for determining distances and elevations and a plane-table for sketching contour lines. A USGS benchmark is visible near the top. The straight white lines represent survey transects. Note the ‘US’ marking on the canteen: many of the USGS field supplies were obtained from Army surplus.” [Osher Map Library]