Carbon dioxide from Earth’s mantle may trigger some Italian earthquakes
Italy may owe some of its seismic activity to carbon dioxide bubbling up from deep underground. The country’s central Apennine Mountains region has been rattled by several destructive earthquakes in recent years, including the devastating magnitude 6.3 quake that wracked the city of L’Aquila in 2009 (SN: 8/14/09). A new decade-long record of natural carbon dioxide emissions in the area reveals that spikes in CO2 release coincided with the biggest earthquakes. That finding hints that CO2 rising toward Earth’s surface can change pressure along faults to trigger earthquakes, researchers report online August 26 in Science Advances. Understanding the relationship between CO2 and seismicity could someday lead to better earthquake forecasts. Earth naturally releases carbon dioxide when tectonic forces melt carbonate rock in the mantle, a process that frees CO2 (SN: 10/1/19). That CO2 rises, gathers in pressurized pockets in Earth’s crust and seeps into groundwater that feeds springs aboveground. Previous studies have...