On the afternoon of Jan. 5, 2019, the
remote jungle of Acre, Brazil began to shake. The trees swayed, the ground
moved up and down and animals scurried for cover. At 2:25 p.m. local time, the
Seismological Observatory of the University of Brasilia registered a magnitude 6.8
(Mww) quake with an epicenter 55 miles west of Tarauaca, Brazil, and 204 miles
east of Pucallpa, Peru with depth of 575 kilometers.
Minutes later, a tiny device,
inside a concrete bunker at the South Dakota School of Mines & Technology
registered the same earthquake–and an email alert is sent to the phone of Kevin
Ward, Ph.D., assistant professor of geology and geological engineering at Mines.
“I can see earthquakes around the world,” says Ward.
The Mines seismographic bunker was
built into the side of a hill behind campus in 1960. It includes a pillar of
concrete that extends 25 feet into the ground the connects the bunker with the
earth. For decades the seismometers in this bunker were part of the USGS
Global Seismographic Network. But, as the university and the town of
Rapid City grew–the level of local noise and vibrations interfered with the older
mechanical seismometers. These instruments are so sensitive to vibration they
can pick up trains, cars, and even footsteps nearby. “I can see cars driving by
and tell if they are going up or down the nearby hill,” says Ward.
The seismographic bunker at Mines
was abandoned in the mid 1990’s due to local noise interference. Today the USGS
maintains a research
grade seismometer in a remote part of the western Black Hills near
the Wyoming border that is part of a global network of earthquake detectors. But
when Ward came to Mines in 2018, he realized the potential of the old bunker as
an education tool and location for a next generation seismometer.
Ward purchased a small digital
seismometer, it can fit in one hand. The
instruments inside the clear plastic box include a computer and a geophone.
This single seismometer replaces three rooms full of the old mechanical
seismograph equipment. “Basically, you can buy these for a few hundred
dollars. It’s something armatures can
buy,” says Ward.
The device that can track
earthquakes around the world and send data in real time. Special software can also be used to filter
out background noise, like passing cars and trains–and watch for the unique
signature made by a large earthquake happening somewhere around the world. The
Mines seismograph, along with others around the world are registered on the Raspberry
Shake Network here.
The SD Mines Museum
of Geology is also installing a Raspberry Shake Seismometer that
visitors can view first hand. The interactive exhibit will allow guests to jump
up and down on the floor and see the waves they create in real-time. The Museum
featured the new device in a post on their Facebook page here
and officials plan to have the new exhibit up and running by mid-March.
On top of this, Ward also brought
in a new earthquake display monitor, now installed in the Mines Department
of Geology and Geological Engineering. The system uses USGS
Earthquake display data on a map that show the most recent earthquakes around
the globe in real time.