Rising Tides, Clean Coal, and Arctic Land Grabs
“What weather forecasters do aboveground, we do underground,” says Harvey Thorleifson, director of the Minnesota geologic survey, adding that like climatology and meteorology, geology plays a major role in preparing for climate change. “Layers of rock record the earth’s history,” Thorleifson says, “and that will help us understand what a future climate might be like.” Greater access to geologic maps will help developers adapt to changing weather patterns by better understanding their local geology to predict sinkholes, collapsing building foundations, or flooding in low-lying communities. OneGeology may also help utilities locate geologic structures that can trap carbon dioxide underground, an essential part of the “clean coal” initiative.
As geology plays a role in the world’s changing borders, it has been critical to the current “land grab” in the Arctic, where melting ice has prompted Russia, Canada, Denmark, and the United States to send surveyors to find out what offshore land belongs to whom. “The Arctic, for energy reasons, is hugely interesting to everybody,” Lyttle says. “Geological mapping will help settle that dispute.”
Rocky Times The colors in the map above represent the age of the earth’s rock. Along the Mid-Atlantic Ridge between Europe and the Americas, as magma came to the surface, the plates moved east and west. Therefore, away from the ridge’s center the deposits are older and older. Forty years ago geologists developed the theory of plate tectonics by dating the rocks along these ridges and identifying the symmetrical pattern seen here in pink to yellow to orange, red, and green. Elsewhere on the map are similar spreading points where the earth’s plates split, collided, or slid past each other.
A Tour Through OneGeology
▪ Enter the Portal and let the map load. The starting map—known as the Blue Marble: Next Generation map—is derived from a year's worth of images from NASA's earth observatory satellites, including MODIS.
▪ To see geological maps, click on the "Add Layers" tab on the upper right. Click on the "+" sign next to the country to see the data sets that OneGeology has available.
To see a stratigraphic map of the United States, for example, select the "North America" region and then the map called "North America USGS 1:5 M Geology." Click on this map and the site will load a map of North America at a scale of one to 5 million.
▪ By selecting tools from the toolbar on the left and clicking on the map, you can manipulate the view: The magnifying lenses zoom in and out, the hand lets you reposition the map, and the "i" tool provides in-depth geological information. When you click on any of the maps, wait several seconds for OneGeology to respond to your action by loading the requested data.
▪ To go to the interactive version of the world stratigraphic map published by the Commission for the Geological Map of the World (pictured earlier in this article), go to "Add Layers" and then to the "World" section. Click on the "WORLD CGMW 1:25 M Geologic Units" map.
You can see the age of parts of the earth's crust by using the "i" tool or by matching the colors on this map with the detailed legend on the International Stratigraphic Chart [pdf]. Take a close look at the Mid-Atlantic Ridge between Europe and Africa on one side and the Americas on the other. The bands of rock from different geological ages here were the first evidence that researchers saw for the movement of tectonic plates.
