This map is a large format wall map of the geology of the 48 states, with an inset map showing California fault lines and major earthquakes. The map combines SHP and SDF features. USA state boundaries come from the Navteq datasets in SDF format that are included with AutoCAD Map 3D. SHP files for the geology and earthquake data were downloaded from the National Atlas (United States Department of the Interior).
The earthquake’s epicenter was about 60 km (~40 miles) northwest of Richmond, Virginia and occurred in the central Virginia seismic zone- an area of modest (or so we thought), but persistent seismic activity in the Piedmont. This region is laced with ancient faults that formed 200 to 300 million years ago when Virginia was at the frontline in an ugly collision between tectonic plates. I study these fault zones. Today’s temblor makes it clear that these faults are 1) not inactive and 2) have the potential to produce significant and damaging earthquakes. We have much to learn about the stresses that cause faults to slip this far from modern tectonic plate boundaries (in this case at the Mid-Atlantic Ridge some 3,000 km from central Virginia) and the hazards that these old, but restless, faults pose. It’s why we do research at William & Mary. (via Chuck Bailey)
I’m in love with cartography at the moment. I think it’s amazing, especially older cartography. Anything with maps of the world on it, I love looking at and considering buying.
Maps are so beautiful.
“Frequently on the lunar surface I said to myself, ‘This is the Moon, that is the Earth. I’m really here, I’m really here.’” This quote from Alan Bean, Apollo 12, is from an interview he did soon after he returned from the Moon. (via InterplanetSarah)
CryoSat’s exceptionally detailed data have been used to generate this map of sea-ice thickness in the Arctic. Data from January and February this year have been used to show the thickness of the ice as it approaches its annual maximum. Thanks to CryoSat’s orbit, ice thickness close to the North Pole can be seen for the first time. Credits: CPOM/UCL/ESA. (via ESA)