Kara Prior cross-stitches earth science maps; her work includes a series of state bedrock geology maps (see also Reddit) and a bathymetry map of the Great Lakes (above), among other things. She has an Etsy store.
NASA Earth Observatory summarizes recent work in using satellite data to improve our maps of shallow seafloors—where the situation changes more often than traditional sonar methods can track—by, among other things, using a laser altimeter system on one of NASA’s satellites.
In 2021, Nathan Thomas and Lola Fatoyinbo of NASA’s Goddard Space Flight Center, along with colleagues from three countries, took another step by mating ICESat-2 measurements with images from Copernicus Sentinel-2 to derive bathymetry at better resolution. The team mapped the shallows down a depth of 26 meters (85 feet) around Biscayne Bay in Florida, the Gulf of Chania in Crete, and the island of Bermuda.
Thomas and colleagues compared their satellite-derived bathymetry with maps made from traditional topographic surveys, multibeam sonar, and nautical soundings. Their new maps had a resolution of 10 meters, improving upon the current 115-meter resolution dataset for Crete and the 30- to 90-meter datasets for Florida and Bermuda. The existing data for Florida and Bermuda are composites of lots of sources spanning 63 years, while the ICESat-2/Sentinel-2 maps offer a contemporary assessment of underwater structure.
See also this earlier Earth Observatory item from last year. (Deep water bathymetry is another thing: light can’t get down that far. But out-of-date soundings are less impactful on shipping.)
The Australian government has released high-resolution sea floor map data of the Great Barrier Reef; the data improves the view of the relief by a factor of eight, from 250-metre resolution to 30-metre resolution. The result of a collaboration between James Cook University, Geoscience Australia and the Australian Hydrographic Service, the data “can be used for policy, planning and scientific work. For example, this data is an important input for oceanographic modelling, which we can use to enhance our knowledge of climate change impacts, marine biodiversity, and species distribution.” Press release, data files.
Newsweek looks at efforts by a group of scientists and mariners to map most of the ocean floor by the year 2030. The objective was endorsed by a meeting of GEBCO, the General Bathymetric Chart of the Oceans, last June. The scale of the project is vast:
To date, more than 85 percent of the seafloor has not been mapped using modern methods. Since 70 percent of the Earth is covered in oceans, this means that we quite literally don’t know our own planet. “We know the surface of Mars better than we do the seafloor,” says Martin Jakobsson, a researcher at Stockholm University.
New seafloor maps of the Monterey Bay area have been released as part of the California Seafloor Mapping Program. The maps “reveal the diverse and complex range of seafloor habitats along 130 kilometers (80 miles) of the central California coast from the Monterey Peninsula north to Pigeon Point.” [Leventhal Map Center]
Previously: Mapping the California Sea Floor.
The USGS‘s California Seafloor Mapping Program has produced a set of insanely detailed maps of the sea floor along the California coast. Downloadable as rather hefty PDF files; the map sheets are three feet across as paper maps. Above, a detail from the shaded-relief bathymetry map of the San Francisco area. Boing Boing, Wired.