SEAN Report


  • Anonymous


The following geophysical and meteoritic events were reported by the Scientific Event Alert Network (SEAN), Smithsonian Institution, NHB Stop 129, Washington, D.C. 20560.

A major deflation event at Krafla Caldera (Iceland) began January 6.

The next morning, deflation rate increased, and harmonic tremor began. Earthquakes with maximum magnitude of 4.8 migrated to 30 km north of the caldera January 7 and to 10 km farther north by January 9, indicating magma injection into Krafla's northern fissure zone. Deflation and seismicity continued until January 22. Uplift then resumed but has been interrupted several times, coinciding with periods of harmonic tremor. Earthquakes, many with magnitudes greater than 4, were continuing in early February from the fissure zone. Tilt equivalent to about 110 cm of caldera subsidence was recorded during the deflation event, and up to 2 m of rifting may have occurred 25–50 km north of Krafla. However, no marked change in geothermal activity was observed, and no visible eruption occurred.