You are browsing the archive for seismic waves Archives - The Trembling Earth.

August 2, 2013

The jiggling Earth, or, what are all those squiggles?

Ever since we first formally recorded one more or less a century and a score ago, the seismogram of an earthquake has become an iconic symbol. Oversimplified and unrealistic ones abound, but natural seismograms of earthquakes are distinctly identifiable. Despite the unique details of every earthquake, seismograms around the world are phenomenally similar. The differences among them are actually what allow seismologists to understand the propagation of earthquakes and the structure …


December 17, 2012

Watch the ground ripple in Long Beach

As the seismic waves from a whole host of little earthquakes in L.A. rippled through the basin in 2011, an astonishingly dense array of seismometers deployed in Long Beach captured them in unprecedented detail. Local oil and gas company Signal Hill Petroleum deployed the monitoring instruments in order to conduct an extremely detailed survey of the 3D rock structure beneath their oil fields. Researchers from Caltech and Berkeley struck an agreement with …


March 12, 2011

Animation of Japan quake traversing the U.S.

The data-consolidating institutional consortium IRIS–the Incorporated Research Institutions for Seismology–has a spectacular resource to visualize actual seismic waves propagating around the Earth, that everyone should check out. Here is an animation they put together (they do this for every significant quake) displaying ground motion at recording stations set up around the U.S. You can see the dramatic passage of the seismic waves from the 8.9 quake, and you get glimpses …


Japan quake felt over >2500km radius

One of the many remarkable features about this planet’s largest quakes (like the one that just happened in Japan) is their truly global effect. Be it the tsunami or seismic waves perceptible and imperceptible, most parts of the planet have been touched significantly by the 8.9. Let’s start with perceptible seismic waves, i.e., ones people don’t need sensitive instruments to detect. The elastic energy released by this earthquake was enough …