Penn State Brandywine tracks quake in Mexico
MIDDLETOWN » Making material relevant is a constant challenge for teachers.
This semester, examples in earth science are all too prevalent.
Penn State Brandywine professor Dr. Laura Guertin had a ready-made lesson Friday when the seismometer on campus registered a reading in conjunction with the magnitude 8.1 earthquake that occurred off the southern coast of Mexico. Combined with explanations of hurricanes Harvey and Irma, her courses have been “ripped from the headlines.”
“I want to make what is happening on our planet relevant to students,” she said. “I threw my syllabus out the window the first week of class.”
The most powerful earthquake to hit the nation in a century, tremors were felt late Thursday night by 50 million people as far away as Mexico City and Guatemala City, capital of the neighboring nation of the same name. The epicenter was in the Pacific Ocean, 74 miles off the coast. The earthquake struck when many people were asleep, yet sadly 38 deaths have been recorded. Multiple aftershocks were documented and the shallow, 70-kilometer (112 mile) depth resulted in intense shaking, according to the United States Geological Survey.
The campus underground seismometer, which continually monitors ground motion in the earth’s crust, recorded the first reading at 12:56 a.m. from the body waves that moved through the earth’s interior. It was followed at 5:01 a.m. and 5:04 a.m. by surface waves, those closer to the exterior which cause buildings and other structures to topple.
“The later ones were significant and lasted several minutes,” said Guertin. “They were not strong enough, however, to wake people up from a deep sleep or cause any damage.”
Earthquakes occur when underground rock breaks along a fault. The sudden release of energy creates the seismic waves that cause the ground to shake.
“The rocks are under a lot of stress,” she said. “When there is a release, they just snap and that’s when the destruction happens.”
The campus recorded the shock despite the 2,500-mile distance. The waves were heightened due to the proximity to the earth’s shell.
“It was a significant release,” she added. “It was probably picked up by seismometers around the world.”
Guertin alerted the college community to the reading in an early morning email where she attached the seismograph, or record of ground motion, and an image of the location of the earthquake and historic ones in the region. She noted the area is at a plate tectonic boundary, “so major earthquakes are not unusual or surprising.”
“I also want to clarify some misinformation already going around,” she added. “There is no connection between the current hurricanes in the North Atlantic and this major earthquake.”
The only connection is in Guertin’s classroom, where the natural disasters have resulted in “unfortunate examples” of the subject material. Analyzing the data has prompted the queries which drive the discussion.
“It all starts with the questions and that’s exactly what I want my students to do,” she said. “Many of them are not science majors and these are skills that are applicable in all fields.”