When Doug Wiens approached Minnesota farmers to ask permission to install a seismometer on their land, he often got a puzzled look. "You could tell they were thinking 'Why are you putting a seismometer here?,' " said Wiens, professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis. "'We don't have earthquakes and we don't have volcanoes. Do you know something we don't?' "
Actually, he did. Deep beneath the fertile flat farmland, there is a huge scar in the Earth called the Midcontinent Rift. This ancient and hidden feature bears silent witness to a time when the core of what would become North America nearly ripped apart. If the U-shaped rip had gone to completion, the land between its arms—including at least half of what is now called the Midwest—would have pulled away from North America, leaving a great ocean behind.
Weisen Shen, a postdoctoral research associate with Wiens, will be presenting seismic images of the rift at the annual meeting of the Geological Society of America (GSA) Sept. 25-28. The images were made by analyzing data from Earthscope, a National Science Foundation (NSF) program that deployed thousands of seismic instruments across America in the past 10 years.
At last, the real reason Lex Luthor was in Smallville, to split open the fault and create beach-front property in the Midwest.
| Links |
printed from SoylentNews, Seismometers are Giving Scientists a Clearer Look at a Giant Scar Under American Midwest on 2024-04-25 05:29:29