One must drill the depths to study how earthquakes are born
In June, UMass hydrogeologist David Boutt boarded the vessel Chikyu, and headed for the coast of Japan. Chikyu’s deck carries the world’s tallest ship-borne drill rig, a 327-foot derrick specially made to drill deeper than ever before—up to 4.34 miles below the sea floor. It’s also fully equipped with scientific laboratories allowing immediate sample analysis.
Boutt was one of more than a dozen scientists from seven nations staffing the research vessel for a six-week cruise. They studied conditions near the clash of two massive tectonic plates, the Eurasian and the Philippine, in one of the most seismically active areas on the planet. Data from the trip will “help us better understand the mechanics of the often massive earthquakes in this very active zone,” Boutt explains.
Boutt is an expert in the mechanics and flow paths of subsurface aqueous fluids, a term for warm, pressurized water that’s been so altered by sediment load, dissolved chemicals, or both that it can’t be called simple water anymore. It moves through fractured rocks and faults and is forced out of ocean floor cracks near accretionary prisms to play an integral role in the genesis of earthquakes and tsunamis, but its relationship to tectonic events is not well understood.
On July 1, Boutt blogged, “Everyone is in a good mood as we reached our target coring zone. We’re busy working on the cuttings recovered.” July 4: “Looks like we have entered into the accretionary prism which could be as old as 8 million years, and we have a 4-million-year unconformity across the transition.”
Boutt’s blog often mentioned treats such as home-cranked ice cream, playing games, and jogging around the heli-deck for fresh air and exercise, all of which help researchers and crew unwind after long work hours away from home.
Other goals of the summer project, led by the Japanese government and known as Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), included installing sensors in deep boreholes to monitor the Earth’s crust for earthquake and tsunami activity. Overall, NanTroSEIZE project organizers say, “This deep sea drilling research opens the new frontier of earth and life science for future of mankind by revealing the system of major earthquakes, global changes and origin of life.”