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.
Postdoctoral researcher Oliver White talks about creating maps of Pluto’s geology from New Horizons flyby imagery.
I have studied this area in great detail, and have defined each unit based on its texture and morphology—for example, whether it is smooth, pitted, craggy, hummocky or ridged. How well a unit can be defined depends on the resolution of the images that cover it. All of the terrain in my map has been imaged at a resolution of approximately 1,050 feet (320 meters) per pixel or better, meaning textures are resolved such that I can map units in this area with relative confidence.
By studying how the boundaries between units crosscut one another, I can also determine which units overlie others, and assemble a relative chronology (or timeline) for the different units; this work is aided by crater counts for the different terrains that have been obtained by other team members. I caution that owing to the complexity of the surface of Pluto, the work I’ve shown is in its early stages, and a lot more is still to be done.
Previously: Mapping Pluto’s Geology.
The European Space Agency has released this false-colour composite image of Ireland based on 16 radar scans by the Sentinel-1A satellite in May 2015. The colours show change over the 12 days of coverage: “The blues across the entire image represent strong changes in bodies of water or agricultural activities such as ploughing. […] Vegetated fields and forests appear in green. The reds and oranges represent unchanging features such as bare soil or possibly rocks that border the forests, as is clear on the left side of the image, along the tips of the island.” [ESA]
For the first time, USGS forecast maps that measure the potential damage from earthquakes in the coming year now include human-induced earthquakes, such as those caused by hydraulic fracking. (Oklahoma looms large for that very reason.) Maps for the western U.S., where a different methodology is used, presume that all earthquakes are natural in that region. [Max Galka]
New Horizons mission scientists have created a geological map of a portion of Pluto’s terrain. “This map covers a portion of Pluto’s surface that measures 1,290 miles (2,070 kilometers) from top to bottom, and includes the vast nitrogen-ice plain informally named Sputnik Planum and surrounding terrain. As the key in the figure below indicates, the map is overlaid with colors that represent different geological terrains. Each terrain, or unit, is defined by its texture and morphology—smooth, pitted, craggy, hummocky or ridged, for example. How well a unit can be defined depends on the resolution of the images that cover it. All of the terrain in this map has been imaged at a resolution of approximately 1,050 feet (320 meters) per pixel or better, meaning scientists can map units with relative confidence.”
A new geologic map of Alaska has been published by the U.S. Geological Survey. From the USGS release: “This map is a completely new compilation, carrying the distinction of being the first 100 percent digital statewide geologic map of Alaska. It reflects the changes in our modern understanding of geology as it builds on the past. More than 750 references were used in creating the map, some as old as 1908 and others as new as 2015. As a digital map, it has multiple associated databases that allow creation of a variety of derivative maps and other products.” The map is available traditionally in two PDF sheets, as well as in geodatabase, Shapefile and other database formats.
Geologic maps of Vesta, the asteroid visited by the Dawn spacecraft between July 2011 and September 2012, have been produced for a special issue of the planetary science journal Icarus. Above, a global geologic map of Vesta, compiled from 15 individual quad maps and using a Mollweide projection (Vesta itself is decidedly non-spheroid, but still).
Previously: Atlas of Vesta.
As I said during the Q&A part of my fantasy maps presentation at Readercon (see previous entry), maps of other worlds in the solar system are usually images from space probes that have been set to a map projection. The key word is usually. On Monday the U.S. Geological Survey released a geologic map of Mars that “brings together observations and scientific findings from four orbiting spacecraft that have been acquiring data for more than 16 years.” Via io9 and Wired.
In The Geology of Game of Thrones, a group of geologists has created a geologic map of Westeros and Essos, as well as an invented geologic history of the planet on which George R. R. Martin’s epic takes place. Via io9.
This isn’t the first time a fantasy world has been looked at through a geologic lens. Karen Wynn Fonstad’s Atlas of Middle-earth took a reasonably rigorous look at the landforms of Middle-earth. And Antony Swithin—a geologist in real life under his real name, William Sarjeant—created a geologic map of his invented island of Rockall (see previous entry).
Previously: Review: The Lands of Ice and Fire.
NASA has released an updated map of the bedrock beneath the Antarctic ice sheet; the map, called Bedmap2, adds considerable detail—a tighter grid and millions of data points—to its decade-old predecessor. The image above exaggerates vertical scale by a factor of 17 to increase visibility. See also this short video.
In my review of Paul Schenk’s Atlas of the Galilean Satellites I noted that the maps of Jupiter’s four largest moons were actually spacecraft imagery placed on a map projection; there were no non-photographic maps. In that context, the geologic map of Io, just out from the U.S. Geological Survey, is both novel and pertinent. The maps are based on Voyager– and Galileo-derived photomosaics of Io’s surface released in 2006, but they’re maps. ASU news release, Universe Today.