Geology & Geophysics
University of Alaska Fairbanks
Historical Earthquakes and Uplift/Subsidence of Sumatra from Coral Growth Rings -- Advanced Version part of MARGINS Data in the Classroom:MARGINS Mini-Lessons
The Sumatra region is prone to earthquakes because it lies at the boundary of two of Earth's shifting tectonic platesâthe Indian Ocean crust is creeping steadily northeast and subducting beneath Sumatra. The steady horizontal movements, and pulses of faster horizontal motion that occur during earthquakes, are recorded by GPS stations on the islands. But GPS has only been around since the 1980s, so it can't tell us about land motions associated with large earthquakes that happened in Sumatra long ago. GPS also lacks precise information on vertical motions, and cannot be installed under water, so GPS measurements of coastal land movements are incomplete. In order to figure out how often large earthquakes happen in the region, scientists have turned to coral micro-atolls. They also use coral records to reconstruct progressive sea level changes. In this lab, students will use data from real corals collected in Sumatra to track the sea-level and earthquake record of the region over the past century.
Historical Earthquakes and Uplift/Subsidence of Sumatra from Coral Growth Rings - Introductory Version part of MARGINS Data in the Classroom:MARGINS Mini-Lessons
The Sumatra region is prone to earthquakes because it lies at the boundary of two of Earth's shifting tectonic platesâthe Indian Ocean crust is creeping steadily northeast and subducting beneath Sumatra. The steady horizontal movements, and pulses of faster horizontal motion that occur during earthquakes, are recorded by GPS stations on the islands. But GPS has only been around since the 1980s, so it can't tell us about land motions associated with large earthquakes that happened in Sumatra long ago. GPS also lacks precise information on vertical motions, and cannot be installed under water, so GPS measurements of coastal land movements are incomplete. In order to figure out how often large earthquakes happen in the Sumatra region, scientists have turned to coral micro-atolls. They also use coral records to reconstruct progressive sea level changes. In this lab, students will use data from real corals collected in Sumatra to track the sea-level and earthquake record of the region over the past century.
