This may come as a surprise, but right this instant, Mount Everest is rising. It’s an imperceptible ascension of the world’s tallest peak (and the rest of the Himalayas along with it) that is caused by the Indian subcontinent smashing into Eurasia. According to Dr. Peter Selkin, UW Tacoma assistant professor of interdisciplinary arts and sciences, the collision of these oceanic plates forces pieces of rock to buckle and fold, and either be pushed up or pushed down. “These two plates are very thick,” he says. ”Essentially, there are two very large chunks of rock smashing into one another, and so the mountains get to be very big as a result.”
Understanding how plate tectonics work and what role they play in the continued rise of mountain ranges is all part of the job for the assistant professor. And now, Selkin, a paleomagnetist (a scientist who studies the record of the Earth’s magnetic field in rocks, sediment, and fossils) is preparing to embark on Bengal Fan Expedition 354, a two-month long expedition (from Jan. 29 to March 31, 2015) to the Indian Ocean aboard the drilling vessel JOIDES Resolution, to study samples of the earth taken from miles down in the ocean floor.
The excursion begins in Singapore, where Selkin and the other scientists will board the ship. At present, the Resolution is in the Indian Ocean, collecting core samples that will be offloaded when the vessel returns to port to collect a fresh crew, restock supplies, and load any specialized equipment that will be necessary for the next leg of the expedition. Once the vessel has reached its designated drilling point, the goal, according to the official summary by the Integrated Ocean Drilling Program (IODP), is to “investigate interaction among the growth of the Himalaya and Tibet, the development of the Asian monsoon and the processes affecting the carbon cycle and global climate.”
Selkin describes the Resolution as “a floating university,” and with nearly 60 scientists of various specialties working around the clock it’s easy to see why.
“There are microbiologists, and there are people looking at sediment grain sizes, shapes and composition. There are people whose job it is to pick through the sediment and look for different kinds of fossils,” Selkin says. “There are four of us that are looking at the records of the earth’s magnetic field being captured in the sediments.”
Selkin’s work aboard the Resolution will be fairly fast-paced, as the analysis of the core samples will be happening while the drilling is going on. “Timing is pretty tight, so everybody has to be working,” Selkin says. “Once they put the drill into the sediment and start getting cores on deck, the core is split in half, so that the scientists can start working immediately.”
The core samples will be used to aid in a multitude of research. According to Selkin, the expedition is looking to gain insight into how much and how fast the Himalayas have risen over “a certain amount of time.” The researchers will also be looking for clues as to whether or not the rise of the mountain chain has ever experienced “starts and stops along the way.” All of this will help to answer the question of what the continued rise of the Himalayas has to do with erosion.
While the Himalayas are rising, various factors like weather, rivers and landslides are wearing them down. “Because of this, it is not entirely clear how fast that erosion is occurring as the mountains have risen,” says Selkin. “This is a big deal because the faster mountains get eroded the higher they can rise.”
In addition to a better understanding of the process of erosion, the samples taken from the ocean floor will provide Selkin and his fellow paleomagnetists a chance to look at the magnetic properties of minerals (primarily iron oxide minerals) as a way to trace environmental processes, such as climate change and pollution. This fits into a strand of Selkin’s work looking at the way sediments record environmental changes.
Because it is so hard to get samples from, the Indian Ocean represents a significant gap in understanding things like environmental change, as well as how the magnetic field has changed over time. Filling in that gap, Selkin’s research will also focus on examining changes in the strength of the Earth’s magnetic field. Understanding the role the field’s overall strength plays will help scientists better predict when it will reverse polarity – something the field hasn’t done in approximately 780,000 years. “A lot of people tell you the field is going to reverse, but no one can tell you when,” Selkin says.
Right now, the strength of the field is decreasing, but the field has decreased in the past without a reversal. “It’s a lot harder to figure out the strength of the field, than it is the flips in polarity,” Selkin says. “We’ve known for a long time that the field has been flipped from north to south, but it’s been unclear how that’s happened and what relationship that has with the strength of the field.”Another aspect of Selkin’s research will be an exploration of how and why the field reverses, or, more to the point, why it doesn’t. As he puts it, “To me, the bigger question is: Why doesn’t the magnetic field reverse?”
There have been periods of time where the magnetic field hasn’t reversed for tens of millions of years, and scientists like Selkin want to know why. That is why finding from Bengal Fan Expedition 354 may be significant. The core samples that will be pulled from miles beneath the Indian Ocean will hopefully provide researchers with a more detailed picture that could change thinking about the Earth’s magnetic field. “We think of our field now as being a typical magnetic field,” says Selkin. “But that might not really be the case.”
Once he returns from the expedition, Selkin hopes to continue his research on the core samples with the help of some UW Tacoma students.
“I’m hoping eventually to get funds to bring on a grad student, but in the meantime, I have a couple of undergrad students who are interested in working on these cores. And I’d be happy to have more if anyone is interested,” Selkin says, laughing. “I’m looking for about three or four students.”
John Burkhardt, Communications, 253-692-4536 or firstname.lastname@example.org