By Rachel Hergett MSU NEWS SERVICE
BOZEMAN
– The Himalaya Mountains are an active site of continental collision, where the
meeting of tectonic plates forces the Earth’s surface to great heights. At the
same time, in the face of extreme conditions, the mountains are also rapidly
eroding.
Mountain
building is closely tied to climate, according to structural geologist Mary
Hubbard, a professor in Montana State University’s Department of Earth
Sciences in the College of Letters and Science. While forces under
the surface of the Earth cause mountains to rise, climate trends, such as
annual monsoons, fill the rivers and send landslides down the valley walls. But
details of this process have not been studied extensively in remote areas like
the high Himalaya. A Sanskrit word meaning “house of snow,” “Himalaya” is the
preferred term used by locals and researchers to refer to the range of
mountains and region they dominate.
This
spring, Hubbard co-led one of two teams of geologists on an interdisciplinary
expedition to Mount Everest led by National Geographic and Tribhuvan University
that sought to fill the scientific void in the Himalaya. It was the first in a
series of Perpetual Planet Extreme Expeditions, a partnership between National
Geographic and Rolex which seeks to understand the scope of climate change in
some of Earth’s most unique environments.
“There
are still a lot of unanswered questions,” Hubbard said.
The
expedition collected wide-ranging data in five fields: biology, glaciology,
meteorology, geology and mapping. It drew more than 30 scientists from eight
countries, including 17 Nepali researchers. National Geographic called it “the
most comprehensive single scientific expedition to the mountain in history.”
“Because
climate impacts so many things, if you only look at plants or only look at
insects, you’re going to miss other things in the record, in the lakes, in the
ice,” Hubbard said.
Geology
teams included MSU doctoral student Bibek Giri and six master’s students from
Tribhuvan’s Tri Chandra campus in Kathmandu, Nepal. Students who grew up in
Nepal tend to be from the capital or villages in the lower hills of the
Himalaya and have limited opportunities to visit the high mountains, Hubbard
said.
Giri
was able to stay with family while the team took introductory courses in
Kathmandu, but the mountains around Everest were unfamiliar.
“I’ve
always loved mountains, loved exploring,” he said. “The geology I knew well,
but I had never been there.”
As
they hiked together toward Everest for three days, Hubbard, Nepalese scientific
leader Anata P. Gajurel and geology team co-leader Aaron Putnam of the
University of Maine would point out specific features—bedrock, fault zones,
areas with landslide activity—to the students on their teams.
“They
had the opportunity to learn from three people from different institutions,
with different expertise,” Hubbard said. “We do better science when we
recognize the diversity of people in the sciences.”
Hubbard’s
geology team was one of two to explore different areas at the base of the
mountain. Her team included Giri and three of the master’s students from Tri
Chandra, which is where Giri studied for his undergraduate and master’s
degrees.
They
hiked to high-mountain lakes in a valley near Everest to collect core samples,
carrying with them specially designed 8-pound pack rafts, paddles, life jackets
and the coring device itself. The two rafts were secured together, forming a
stable platform from which to drop the coring device to the bottom of the lake.
The
samples are vertical segments of the lake’s sediment encased in a clear plastic
tube. Without substantial aquatic life in the high mountain lakes, the sediment
is rarely disturbed. Layers let researchers establish a record of seasonal
cycles on the mountain—the winter cold and spring snowmelt, the monsoons followed
by the dry season. Geologists can then study annual changes to this cycle.
Hubbard’s
team also sampled sand layers farther down the valley, in areas thought to be
stranded lake deposits on the valley walls. Lakes may form from landslide
activity or may be left behind as glaciers retreat, Hubbard explained. Dating
those samples may tell researchers if the lake predates, or is a remnant of,
the last ice age.
The
other geology team, led by the University of Maine, focused on moraines, the
rocks and sediment carried down the mountain with a glacier and deposited in
its path. Drone mapping and samples will allow the team to look at the extent
of the glaciers’ historic paths.
“The
new technology will become part of their lives,” Hubbard said. “As a tool, drones
are incredibly effective in areas of extreme topography, like the Himalaya.”
Once
their samples were collected, the teams met up to hike to Everest Base Camp.
They stayed one night before heading down the mountain.
Giri
said he will return. First, however, he is spending the summer as an intern for
National Geographic in Washington, D.C., compiling reports from all of the
Extreme Expedition teams into one master report and aiding in communication
between the institution, Nepal’s government and Tribhuvan University.
Hubbard
said she was drawn to the project for two reasons: the scope of the research to
be conducted and the number of Nepalese on the team. Without any input in the
scientific process from Nepalese people, the country won’t benefit from
expeditions, Hubbard explained. Her team collected two core samples from each
lake, one to be shipped back to MSU and one to be studied at Tri Chandra in
Kathmandu. There, students and researchers are able to address climate change
while taking regional culture, politics and priorities into account.
“They
can bring together local knowledge and scientific knowledge,” Hubbard said.
