Noatak, a village of about 500 people near the Chukchi Sea, was rattled most recently by a 4.5 quake on Thursday night, July 24, and on the following day by a 5.9 preceded by a 5.3 and followed by multiple aftershocks.

The seismic activity about 12 miles northeast of Noatak is what seismologists call a "quake swarm" or a sequence of similar-sized earthquakes in similar locations over a period of time. This kind of sustained earthquake activity is highly unusual in this remote part of arctic Alaska.

What seems to be puzzling scientists most is there is no earthquake fault near Noatak. A database compiled by the Alaska Division of Geological and Geophysical Surveys shows no active fault structures for hundreds of miles. And yet, in the midst of all this shaking and all these puzzled scientists, seismologists have "suddenly decided to turn off" two monitoring stations.