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2023 Woods Hole Science Stroll

August 12, 2023 | 10am-3pm on Water Street in Woods Hole

Thanks for stopping by the Ocean Bottom Seismic Instrument Center (OBSIC) booth and learning about Marine Seismology.  Below you'll find further information on the activities at our booth (click on each panel to learn more).

What is an OBS?

Seismometers measure motion of the ground.  About 90% of all earthquake-generated fault slip occurs underwater, where the pressure and inaccessibility make measurements difficult.  The Ocean Bottom Seismograph or OBS, was developed for this task.  Scientists use seismometer data to locate earthquakes and to calculate energy released by earthquakes.  By using sensitive seismometers to study small earthquakes, researchers are working to forecast the effects of large earthquakes and the timing of volcanic eruptions.

How Does it Work?

Seismometers work on the principle of mechanical inertia.  The seismometer frame is rigidly attached to the earth.  Inside the seismometer, a mass mounted on a suspension such as a pendulum or a spring sits between two plates of a sensitive capacitor.  During an earthquake, the seismometer frame and capacitor transducer move with the earth, but the suspended mass tends to stay stationary in an inertial reference frame.  The force required to keep the mass centered between the capacitor plates is a measure of ground acceleration.


Create your own StepQuake

This activity mimics the listening that the seismometer does on the seafloor and the output of data is what researchers use in their studies.

BBOBS deploy and recover

Sound In Water

A hydrophone is an underwater device that detects and records ocean sounds from all directions and this activity captures the sound of balloons popping underwater.

Data Analysis

Several scientists in WHOI’s Geology and Geophysics department use data from OBSIC instruments to do seismic imaging, studying locations scattered across the global oceans.


OBSIC at Sea

OBSIC deploys and recovers instruments all around the world.  These images are a small snapshot of what we do.