PANGA lab monitors the West Coast


Jack Belcher, Senior News Reporter

CWU Pacific Northwest Geodetic Array (PANGA) receives data from over 1,200 GPS arrays located mainly around the western United States.

These GPS devices, known as a geodetic monuments, measure the movement of the Earth, which is sent in real time to PANGA on the CWU campus.

According to lead PANGA analyst Marcelo Santillan, CWU is on par with very high level institutions around the country such as MIT and Berkeley. Santillan also said that PANGA has been improving and has been growing.

According to Santillan, these monuments send movement information every second to CWU. The information is very accurate measurements about earthquakes, such as the size of the quake and how it has evolved over time.

This is especially important when there is an earthquake on the coast because tsunamis can occur. The size of a tsunami depends on the size of the earthquake and with these monuments, it is possible to predict how big a tsunami will be and where it will hit land.

These monuments also give sight into the slow process of a volcano inflation. PANGA has a sensor near Mt. St. Helens that detected the ground changing near the 2004 eruption. Since then, the area has stabilized.

“A volcano is like a little pipe with a chamber room at the bottom because of magma,” Santillan said. “When an eruption happens, that is like toothpaste that is just squeezed and it comes out of the top and the ground sort of collapses and shrinks.”

This shrinking in the land is detected by a sensor in the area. PANGA was able to see how the sensor moved closer to the volcano and how the magma chamber was sinking at that time.

Santillan said the best place to set up one of these monuments is somewhere solid that has long roots. These monuments are built to stay well attached to the ground, so the best place is somewhere rocky.

According to PANGA Field Engineer Rex Flake, these monuments are placed all over the U.S., although many of them are close to the West Coast due to high activity levels in the area.

The Juan de Fuca Plate, located adjacent to the North American plate, has been moving underneath the North American plate for around 200 million years, at a rate of about 44 millimeters (1.5 inches) a year. This process is called subduction. Because of this, there is a possibility of a very large earthquake every 300 to 400 years.

According to Flake, the last big quake was in the 1700s.

“Just make sure that you are over here in Ellensburg and not in Seattle,” Flake said. “There is going to be a lot more shaking over there.”

There are also a lot of shallow faults in the area and when a large subduction happens, it could set off the rest of the smaller ones, causing a “double whammy.” It’s also a possibility that if this happens, Mt. Rainer could start to shake, which would cause mud flows that affect the entire area.

Flake said that this is unlikely because Mt. Rainer has remained stagnant for a long time. The most active volcano in the state of Washington is Glacier Peak.

“It is just north of us, not a lot of people even know about it,” Flake said.

Other than Mt. St. Helens, Glacier Peak had some of the most recent activity. However, the peak is sort of a blind spot for PANGA because it’s so hard to reach the area. Flake and Walter Szeliga, another CWU professor involved with PANGA, want to get a monument at the location.

“It’s a two-day hike just to get to the base of the mountain,” Flake said. “It’s a wilderness area, so you can’t fly in with a helicopter.”

Because of this blind spot, PANGA knows little about Glacier Peak. While Flake would like to see more data on the area, he is sure that PANGA would see warnings before an eruption.