Elizabeth Berg of the University of Utah installs a seismometer on the Denali Fault near Cantwell. (Ned Rozell | For the Juneau Empire)

Elizabeth Berg of the University of Utah installs a seismometer on the Denali Fault near Cantwell. (Ned Rozell | For the Juneau Empire)

Jabbing sensors into the Denali Fault

Scientists are performing some rare fieldwork.

PANORAMA MOUNTAIN — “For some reason, when I come to this terrain, I know something’s been pulverized.”

Cole Richards says this while watching three companions kick their steps Chilkoot-Pass style into an abrupt hill. The slope rises from the pancake floodplain of the Nenana River just behind him. The landscape here seems a bit confused.

Richards, a graduate student in seismology at UAF’s Geophysical Institute, is standing in snowshoes on the Denali Fault, atop a foot of compacted snow. The Denali Fault is a weak spot in Earth’s crust that has maintained a frown across the middle of Alaska with its continual jerky movement. One of the most obvious strike-slip faults in the world (where land on one side of the fault creeps in the opposite direction of land on the other), the Denali Fault unzipped more than 200 miles of tundra and ice during a giant 7.9 earthquake in 2002.

Richards and nine other scientists are performing some rare February fieldwork here, where the fault didn’t rip during 2002. They are driving 400 seismometers into frozen soil. Their goal is to get exquisite detail on this geological feature that a person can see on a flight from Anchorage to Fairbanks as a straight line of lowlands and glacier ice in the middle of white Alaska Range mountains.

The 10 scientists, including pairs from both Utah and South Dakota, have divided their labor into three sectors. Three people have driven up to Nenana and are working southward along the Parks Highway. Three have driven to Trapper Creek and are moving northward.

The team of four here beneath Panorama Mountain are sipping from water bottles on a snowy hilltop at what team leader Carl Tape calls ground zero, exactly on the Denali Fault. They have just snowshoed a straight path about a kilometer southward toward the Nenana River, and have returned on that same line.

While the snow compacted from the passage of four people firms into a trail, the researchers relax next to 10 yellow bags, half sunk in snow. Inside each bag is a six-pack of what they call nodes, portable ground-motion sensors that look like large oil filters with steel spikes poking from the bottom.

Here at what Tape estimates is a straight line crossing the fault, the scientists will shove the nodes into the ground every 100 feet, orient them to the north, turn them on, and bury them beneath snow.

Tape, the Geophysical Institute seismologist, is in no rush on this first day of deployment. A few years ago, he learned the value of waiting for the trail to harden while placing similar instruments over the fault where it crosses the Richardson Highway.

Their 94 instruments will remain quietly in place until their batteries wane in March. The other teams will install 306 more nodes closer to the highway from Trapper Creek to Nenana. Those teams will install seismometers about 1 kilometer from one another.

Near the end of March 2019, someone will retrieve all of the nodes. By then, the instruments will be full of information of how much the ground shook, and in which direction. The results should tell seismologists quite a bit more about the Denali Fault and what lies deep beneath it.

On this day, just a few weeks past the coldest day in North America’s history (minus 81 in 1947) and with endless sunshine a few months ahead, many Alaska scientists are in their offices either planning fieldwork or working up last summer’s numbers. Why did the seismologists choose mid-February to deploy their instruments?

One reason is because the spikes on the nodes can bite into frozen ground and remain cemented there by ice, Tape said. Another is that nature’s version of vandals, bears, will probably remain in hibernation for the length of the experiment.


• Since the late 1970s, the University of Alaska Fairbanks’ Geophysical Institute has provided this column free in cooperation with the UAF research community. Ned Rozell (ned.rozell@alaska.edu) is a science writer for the Geophysical Institute.


With Panorama Mountain in the background, from left, Lynn Kaluzienski, Elizabeth Berg, Cole Richards and Carl Tape take a break from stomping out a 1-kilometer snowshoe line across the Denali Fault near Cantwell. (Ned Rozell | For the Juneau Empire)

With Panorama Mountain in the background, from left, Lynn Kaluzienski, Elizabeth Berg, Cole Richards and Carl Tape take a break from stomping out a 1-kilometer snowshoe line across the Denali Fault near Cantwell. (Ned Rozell | For the Juneau Empire)

More in News

(Juneau Empire file photo)
Aurora forecast for the week of March 25

These forecasts are courtesy of the University of Alaska Fairbanks’ Geophysical Institute… Continue reading

The aging Tustumena ferry, long designated for replacement, arrives in Homer after spending the day in Seldovia in this 2010 photo. (Homer News file photo)
Feds OK most of state’s revised transportation plan, but ferry and other projects again rejected

Governor’s use of ferry revenue instead of state funds to match federal grants a sticking point.

The Shopper’s Lot is among two of downtown Juneau’s three per-hour parking lots where the cash payments boxes are missing due to vandalism this winter. But as of Wednesday people can use the free ParkSmarter app to make payments by phone. (Mark Sabbatini / Juneau Empire)
Pay-by-phone parking for downtown Juneau debuts with few reported complaints

App for hourly lots part of series of technology upgrades coming to city’s parking facilities.

A towering Lutz spruce, center, in the Chugach National Forest is about to be hoisted by a crane Tuesday, Oct. 27, 2015, for transport to the West Lawn of Capitol Hill in Washington, D.C., to be the 2015 U.S. Capitol Christmas Tree. (Photo courtesy of the U.S. Forest Service)
Tongass National Forest selected to provide 2024 U.S. Capitol Christmas Tree

Eight to 10 candidate trees will be evaluated, with winner taking “whistlestop tour” to D.C.

Annauk Olin, holding her daugher Tulġuna T’aas Olin, and Rochelle Adams pose on March 20, 2024, after giving a presentation on language at the Alaska Just Transition Summit in Juneau. The two, who work together at the Alaska Public Interest Research Group’s Language Access program, hope to compile an Indigenous environmental glossary. (Photo by Yereth Rosen/Alaska Beacon)
Project seeks to gather Alaska environmental knowledge embedded in Indigenous languages

In the language of the Gwich’in people of northeastern Alaska, the word… Continue reading

The room where the House Community and Regional Affairs Committee holds its meeting sits empty on Tuesday. A presentation about an increase in the number of inmate deaths in state custody was abruptly canceled here. (Claire Stremple/Alaska Beacon)
Republican lawmakers shut down legislative hearing about deaths in Alaska prisons

Former commissioner: “All this will do, is it will continue to inflame passions of advocacy groups.”

(Michael Penn / Juneau Empire file photo)
Police calls for Monday, March 25, 2024

This report contains public information from law enforcement and public safety agencies.

Employees at the Kensington Mine removing tailings from Johnson Creek on Feb. 17 following a Jan. 31 spill of about 105,000 gallons of slurry from the mine, although a report by the mine’s owners states about half slurry reached the creek 430 meters away. (Photo from report by Coeur Alaska)
Emergency fisheries assessments sought after 105,000-gallon tailings spill at Kensington Mine

Company says Jan. 31 spill poses no risk to Berners Bay habitat, but NOAA seeks federal evaluation.

Dozens of people throw colors in the air and at each other during a Holi festival gathering Monday night outside Spice Juneau Indian Cuisine. (Mark Sabbatini / Juneau Empire)
Holi festival in Juneau revives colorful childhood memories for some, creates them for others

Dozens toss caution and colored cornstarch to the wind in traditional Hindu celebration of spring

Most Read