ANN ARBOR—An earth scientist doing research at sea? Isn’t that a contradiction in terms? Not according to University of Michigan associate research scientist Josep Pares, who is spending six weeks aboard an enormous research ship positioned right over one of our planet’s most active earthquake zones.

Pares is part of an international team participating in a complex ocean-drilling project called the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE). Its mission: to drill, sample and instrument for the first time the earthquake-causing (seismogenic) portion of Earth’s crust, where violent, large-scale quakes have occurred repeatedly throughout history.

“The Nankai Trough, off the coast of Japan, is a subduction zone—a place where two tectonic plates converge,” Pares said. “When two plates meet, one subducts, or sinks, under the other, and this convergence between plates produces major earthquakes. By looking at the physical properties of the sediments that are involved in that subduction zone, we hope to learn how earthquakes work.” Samples will be collected in order to study the frictional properties of the rock, and sensors will be installed deep beneath the sea floor to record earthquakes up close.

The research ship, Chikyu, is almost twice as long as a football field, and is outfitted with a drilling rig capable of drilling to a depth of more than four miles to retrieve core samples for study by Pares and the other 24 scientists on the expedition (one of three Chikyu expeditions this year and next).

In addition to state-of-the-art laboratory facilities, Chikyu offers scientists individual cabins, a cafeteria, conference rooms and even a small gym, a hot tub and a Japanese tea ceremony room, but life onboard won’t be like a Carnival Cruise. Research will be going on 24/7, with scientists working 12-hour shifts.

“Once we start recovering sediment, we can’t afford to stop,” Pares said. “We want to produce as much data as we can.” While initial analyses will be done on the ship, Pares and the other researchers will study the samples in greater detail in their own labs after the cruise is over. His particular contribution will be analyzing the magnetic properties of recovered sediments.

“My Japanese research partner and I study reversals of Earth’s magnetic field as recorded in sediments, and in collaboration with the paleontologists on the team, we will determine the age of the rocks and the rate at which sedimentation occurred.”

In addition, Pares is interested in magnetism as a physical property of the sediments.

“When sediment forms in the ocean floor, the particles are oriented by gravity, so they’re weakly aligned,” Pares said. “But subduction changes the orientation of the particles, and their orientation determines where fault fractures will form in the subduction zone.”

The drilling project is “truly an inside look into a subduction factory—the zone that produces the largest earthquakes on the planet,” Pares said. “For an earth scientist, that’s a real thrill.”

It’s timely, too. “In just five years we will celebrate the 100th anniversary of the once-controversial concept of continental drift,” he said. “When Alfred Wegener first proposed what he called ‘continental mobility’ in 1912, the hypothesis was rejected. Not until the 1960s did it gain acceptance. Now, almost 100 years later, we have not only solidified the concept of plate tectonics, but we are about to explore directly the zone where tectonic plates converge and ultimately are responsible for the growth of continents—the most beautiful expression of a dynamic Earth.”

U-M has a long history of involvement with the Integrated Ocean Drilling Program (IODP), which operates the Chikyu expeditions. Over the years, U-M professors, research scientists and students have participated in scientific cruises, and U-M researchers also have played important advisory roles in the program.

To follow the progress of the Chikyu expeditions, watch for weekly updates at: http://www.jamstec.go.jp/chikyu/eng/.

For more information:
Josep Pares: http://www.lsa.umich.edu/geo/geo_detail/0,2764,16407%255Fpeople%255F64917770,00.html

Integrated Ocean Drilling Program: http://www.iodp.org/

Josep ParesIntegrated Ocean Drilling ProgramTo follow the progress of the Chikyu expeditions, watch for weekly updates