Civil War historians are hailing it as an important new way to visualize the toll of the huge battle outside Sharpsburg, Md., in 1862.
“Every one of us who’s looked at this absolutely flips out,” said Garry Adelman, chief historian for the Washington-based American Battlefield Trust, which works to preserve historic battlefields. “This will reverberate for decades.”
The map is the only one of its kind known to exist. It was digitized by the New York Public Library, which owns it, and was spotted online by local historians a few weeks ago.
The map doesn’t just mark graveyards, it notes the burial locations of specific regiments and brigades—and in 45 cases, individual soldiers.
Last month the Washington Post published a feature on the impact of Interstate 80 on wildlife migrations in Wyoming, and how climate change would affect animals’ ability to move to new habitat as their usual stomping grounds are made unsuitable by global warming. The print version (above) and online version have related maps—one static, one dynamic—that illustrate wildlife paths and how they are stymied by the highway, as well as places where overpasses and tunnels might help. [Lauren Tierney]
Fall foliage maps, which show the best times and places to observe autumn leaves, have been a thing for a good long while. The Washington Post’s take on them is something earnestly next level, with a detailed explanation of the biology and satellite images showing the change in colour across the United States. (I don’t need fall foliage maps: I live on an acre of beech and maple forest and get all the fall colours right outside my window, though here in Canada the leaves are almost all on the ground by now.)
Last month the Washington Post gained access to ARCOS, the U.S. Drug Enforcement Agency’s database of controlled substance transactions, which tracks the path, from manufacturer to pharmacy, of every pain pill in the United States. The Post’s initial analysis found that some 76 billion oxycodone and hydrocodone pills were distributed in the U.S. between 2006 and 2012, that only a few companies manufactured and distributed the bulk of the pills, and some regions of the country were utterly saturated with the pills. That’s where the maps come in: the Post has county-level maps of all this data.
Comparing county-level maps of opioid overdose deaths and pill shipments reveal a virtual opioid belt of more than 90 counties stretching southwest from Webster County, W.Va., through southern Virginia and ending in Monroe County, Ky. This swath includes 18 of the top 20 counties ranked by per-capita prescription opioid deaths nationwide and 12 of the top 20 counties for opioid pills distributed per capita.
The Washington Post maps disasters in the United States, with a page that shows maps of flood warnings, tornadoes and hurricanes, extreme heat and cold (see above), wildfires, lightning, and earthquakes and volcanoes. In the wake of a natural disaster there’s usually someone suggesting that the victims are at fault for living in a disaster zone. The WaPost’s maps have an answer to that: “It turns out there is nowhere in the United States that is particularly insulated from everything.”
Winter isn’t quite done with us yet where I live. And with that in mind, here’s a neat animated map from the Washington Post that shows the total accumulated snowfall in the contiguous United States. The link includes 48-hour snowfall accumulation maps, satellite imagery, and a map showing which areas of the lower 48 have had more or less snowfall than Washington, D.C. I imagine these maps will have to be updated now.
In the 1770s British surveyor George Gauld mapped the Florida Keys, taking careful note of the location and depth of Florida reefs. A study published last month in Science Advances compares Gauld’s maps with modern-day satellite imagery and concludes that half of the area occupied by coral in the eighteenth century has disappeared. As the Washington Post reports, the cause of the coral’s disappearance is unclear, though several potential human and natural factors are put forward. [WMS]
Some of the most striking maps of the recent bout of hurricanes have involved the sheer amount of water dropped by these storms. (See previous posts on Harvey and Irma.) Above, a is a short NASA video showing Maria’s track through the Caribbean, dumping water in its wake.
The New York Times is collecting several maps on two web pages. The first page deals with subjects like rainfall, river level, current and historical hurricane tracks, damage reports, and cities and counties under evacuation orders. Maps on the second page look at Harvey’s impact on the Houston area.
Kenneth Field critiques the National Weather Service’s decision to add more colours to their precipitation maps (see above). “Simply adding colours to the end of an already poor colour scheme and then making the class representing the largest magnitude the very lightest colour is weak symbology. But then, they’ve already used all the colours of the rainbow so they’re out of options!”
Today, print subscribers to the New York Times were treated to a fold-out map showing a choropleth map of the 2012 election results at the ZIP code level (above). “The map is part of a special election section that aims to help explain the political geography of the United States — identifying where people who are conservative and liberal live and pointing out how physical boundaries, like the Rio Grande and the Cascade Mountains, often align with political ones,” writes the Times’s Alicia Parlapiano.
Parlapiano’s piece is in fact a lengthy tutorial on how to read election maps, along the lines of the pages I linked to in last week’s post on election map cartography—it outlines the problems of state-level election maps and choropleth maps that privilege area over population, for example, and shows some other ways of depicting the results.