Charlie Mitchell has made a time-lapse map showing earthquakes in New Zealand over the past decade (January 2008 to December 2017), scaled by magnitude. On Twitter he explains that he excluded earthquakes less than 3.0 magnitude but still ended up with around 20,000 of them. Simple, without a lot of supporting information, but effective.
The York Museum Gardens’ Geological Mosaic Map is a four-metre-square pebble mosaic that depicts the Yorkshire part of William Smith’s 1815 geological map of Great Britain—a copy of which is held at the adjacent Yorkshire Museum. The mosaic was commissioned in 2015 and created by mosaic artist Janette Ireland, who “used many imaginative devices—including fossils, both real and formed from pebbles, discarded stone from the minster and tiny millstones made of millstone grit—to represent the ideas which Smith was demonstrating in his map. […] The pebbles in the mosaic reflect the colours Smith used in his map, but genuine Yorkshire rocks are displayed in the flower beds on either side of the mosaic, alongside strips of the pebbles used to represent them.” Photo gallery. [WMS]
This crowdsourced map of collapsed and damaged buildings in Mexico City (in Spanish) appeared shortly after the 7.1-magnitude earthquake hit central Mexico on 19 September [via]. NASA also produced a map, based on radar data from the ESA’s Copernicus satellites that compared the state of the region before and after the quake. Interestingly, the data was validated against the crowdsourced map.
The New York Times produced maps showing the pattern of damage in Mexico City and the extent and severity of earthquake shaking (the Times graphics department’s version of the quake’s Shake Map, I suppose) as well as how Mexico City’s geology—it was built on the drained basin of Lake Texcoco—made the impact of the quake much worse.
Science fiction/fantasy novelist Alex Acks, a geologist by training, has some issues with Middle-earth’s mountain ranges. “Middle-earth’s got 99 problems, and mountains are basically 98 of them.” Basically it comes down to how Tolkien’s mountain ranges intersect at right angles—and mountains don’t do that.
And Mordor? Oh, I don’t even want to talk about Mordor.
Tectonic plates don’t tend to collide at neat right angles, let alone in some configuration as to create a nearly perfect box of mountains in the middle of a continent. […]
To be fair to J.R.R. Tolkien, while continental drift was a theory making headway in the world of geology from 1910 onwards, plate tectonics didn’t arrive on the scene until the mid-50s, and then it took a little while to become accepted science. (Though goodness, plate tectonics came down—I have it on good authority from geologists who were alive and in school at the time that it was like the holy light of understanding shining forth. Suddenly, so many things made sense.) Fantasy maps drawn after the 1960s don’t get even that overly generous pass.
And here I thought Tolkien’s mountains were better than most—but then I’m no geologist, and also than most may not be saying that much.
NASA Earth Observatory notes the release of a new map of global landslide susceptibility that models the risks of landslides that are triggered by heavy rain. “The map is part of a broader effort to establish a hazards monitoring system that combines satellite observations of rainfall from the Global Precipitation Measurement (GPM) mission with an assessment of the underlying susceptibility of terrain.” [Geographical]
The PBDB Navigator is a map-based interface to the Paleobiology Database, which among other things includes the locations of every fossil find. A map of every fossil site seems straightforward enough, but there are hidden depths to this one: you can filter by taxonomy (want to look up the fossil sites for eurypterids or tyrannosaurs? no problem!) or by geologic period, but what’s especially neat is that you can factor in continental drift: when searching by geologic period (the Permian, for example), you can show the continents as they were positioned during that period (see above). More at Popular Mechanics. [Leventhal]
William Smith’s 19th-century geological maps of Britain are now available online via an interactive map interface. [Maps Mania]
The Smithonian’s Earthquakes, Eruptions and Emissions interactive map “is a time-lapse animation of volcanic eruptions and earthquakes since 1960. It also shows volcanic gas emissions (sulfur dioxide, SO2) since 1978 — the first year satellites were available to provide global monitoring of SO2.” [Axis Maps]
Another profile of ocean cartographer Marie Tharp, this time from Smithsonian.com’s Erin Blakemore. As Blakemore recounts, Tharp crunched and mapped the sonar sounding data collected by her collaborator, Bruce Heezen; her calculations revealed a huge valley in the middle of a ridge in the North Atlantic seafloor.
“When I showed what I found to Bruce,” she recalled, “he groaned and said ‘It cannot be. It looks too much like continental drift.’ … Bruce initially dismissed my interpretation of the profiles as ‘girl talk’.” It took almost a year for Heezen to believe her, despite a growing amount of evidence and her meticulous checking and re-checking of her work. He only changed his mind when evidence of earthquakes beneath the rift valley she had found was discovered—and when it became clear that the rift extended up and down the entire Atlantic. Today, it is considered Earth’s largest physical feature.
When Heezen—who published the work and took credit for it—announced his findings in 1956, it was no less than a seismic event in geology. But Tharp, like many other women scientists of her day, was shunted to the background.
The Smithsonian’s Ocean Blog has a profile of ocean cartographer Marie Tharp, whose discovery of the Mid-Atlantic Ridge’s rift valley provided hard evidence for the theory of plate tectonics.
It’s an older map, but one I hadn’t seen before: the USGS’s map of the principal aquifers of the United States. [Christopher Tucker]
Previously: Global Groundwater Map.
“New Orleans and surrounding areas continue to sink at highly variable rates due to a combination of natural geologic and human-induced processes,” according to the findings of a new study that maps the rate at which New Orleans is sinking.
The maps were created using data from NASA’s Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), which uses a technique known as interferometric synthetic aperture radar (InSAR). InSAR compares radar images of Earth’s surface over time to map surface deformation with centimeter-scale precision. It measures total surface elevation changes from all sources—human and natural, deep seated and shallow. Its data must be carefully interpreted to disentangle these phenomena, which operate at different time and space scales. UAVSAR’s spatial resolution makes it ideal for measuring subsidence in New Orleans, where human-produced subsidence can be large and is often localized.