Category: Geology

Unified Geologic Map of the Moon

Published on by Jonathan Crowe

A new unified geologic map of the Moon, based on digital renovations that updated 1970s-era geologic maps to match more recent topographic and image data gathered by lunar orbiters, was released by the USGS last month. The map is “a seamless, globally consistent, 1:5,000,000-scale geologic map”; the paper version (25 MB JPEG) provides azimuthal projections beyond the 55th parallels and an equirectangular projection between the 57th parallels. [Geography Realm]

Previously: Lunar Geology and the Apollo Program.

Update, 22 April 2020: Version 2 of this map was released in March to address a number of errors in the first version.

First Geologic Map of Titan

Published on by Jonathan Crowe
Geologic map of Titan
NASA/JPL-Caltech/ASU

The first global geologic map of Titan, based on radar and infrared data from the Cassini probe, has been released.

The map legend colors represent the broad types of geologic units found on Titan: plains (broad, relatively flat regions), labyrinth (tectonically disrupted regions often containing fluvial channels), hummocky (hilly, with some mountains), dunes (mostly linear dunes, produced by winds in Titan’s atmosphere), craters (formed by impacts) and lakes (regions now or previously filled with liquid methane or ethane). Titan is the only planetary body in our solar system other than Earth known to have stable liquid on its surface—methane and ethane.

The map is the result of research published today in Nature Astronomy.

Previously: Titan in Infrared; Mapping Titan with VIMS; A Topographic Map of Titan.

Lunar Geology and the Apollo Program

Published on by Jonathan Crowe
Geologic Map of the Copernicus Quadrangle of the Moon
H. H. Schmitt, N. J. Trask and E. M. Shoemaker, “Geologic Map of the Copernicus Quadrangle of the Moon,” 1967. USGS.

Planetary geologist David Rothery writes about the early attempts to map the Moon’s geology, both before and after the Apollo program. There was a symbiotic relationship between the map and the mission: maps suggested where landings might be most profitable from a geological perspective; and field work by the astronauts informed later moon maps.

Mapping Ground Displacement from the California Earthquakes

Published on by Jonathan Crowe
NASA/JPL-Caltech

This interferogram shows the ground displacement caused by last week’s earthquakes in southern California. Produced by NASA’s Jet Propulsion Laboratory, it’s based on synthetic aperture radar (SAR) images from JAXA’s ALOS-2 satellite taken both before (16 April 2018) and after (8 July 2019) the earthquakes. Each colour cycle represents 12 centimetres (4.8 inches) of ground displacement.

Mapping the Sulawesi Earthquake and Tsunami

Published on by Jonathan Crowe
The New York Times (detail)

Last week a magnitude-7.5 earthquake struck the Indonesian island of Sulawesi, triggering a tsunami that struck the city of Palu with far more force than expected. The New York Times has multiple maps and aerial images of the damaged areas; NASA Earth Observatory has before-and-after Landsat imagery.

Mapping the 2018 Kīlauea Eruption

Published on by Jonathan Crowe

Last week new lava vents opened in the Kīlauea volcano’s eastern rift zone, with fissures destroying a number of homes in the Leilani Estates subdivision of the island of Hawai‘i’s Puna District. Here are some maps.

USGS

The Washington Post’s coverage is typically first rate, its maps providing both detailed coverage and context: start there. More detailed maps come from the Kīlauea section of the USGS’s Volcano Hazards Program website, with fissure maps of the entire eastern rift zone (see above) and thermal maps of the Leilani Estates fissures receiving daily or near-daily updates.

The eruption was preceded and accompanied by a number of earthquakes; NOAA has created an animated map showing the incidence, magnitude and depth of the earthquakes that took place during the week of the eruption.

Map of the Late Jurassic World

Published on by Jonathan Crowe

Paleoartist Julio Lacerda has produced a pictorial map of the world as it was during the Late Jurassic (163½ to 145 million years ago). Available via Studio 252MYA, which sells paleontology-related swag (we have their Lambeosaurus pillow—it was a housewarming gift), it comes as either as a poster or as a framed print, and in two sizes; prices range from $26.50 to $142. Julio is threatening to do maps of other periods, which I hope he follows through on.

Marie Tharp on the BBC World Service

Published on by Jonathan Crowe

Still another profile of ocean cartographer Marie Tharp, this time from the BBC World Service’s Witness program: it’s a nine-minute audio clip called “Mapping the Ocean’s Secrets.” [Osher]

On the WMS Facebook group, Bert Johnson had this to say about this latest profile: “Hers is a standout story, but I wish some of these journalists who keep running these would spend some time and effort discussing some of the other women—known and unknown—who made contributions and helped open the doors of cartography to women.”

Geological Mosaic Map

Published on by Jonathan Crowe
York Museum Gardens

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]

Mapping the Earthquake in Central Mexico

Published on by Jonathan Crowe
The New York Times

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.

‘The Messed Up Mountains of Middle-earth’

Published on by Jonathan Crowe

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.

Mapping Global Landslide Susceptibility

Published on by Jonathan Crowe
Image: Jesse Allen. Landslide susceptibility data: Thomas Stanley and Dalia Kirschbaum (NASA/GSFC). Topographic data: SRTM. (NASA Earth Observatory)

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]

Mapping Fossil Sites

Published on by Jonathan Crowe

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]