Originally posted by jadedANDcynical
reply to post by MoorfNZ
Has there been any kind of determination as to the reason for so many 0 depth quakes in Nevada?
I've been watching those for a bit and there are quite a few at 0 depth, which indicates a surface event if I am correct.
I notice that they are all in close proximity with one a other in a mountainous region. Could it be mining activity of some sort?
Just seems odd to me is all.
Nevada Seismologists are keeping a close eye on an area southwest of Hawthorn where hundreds of earthquakes have been detected since Sunday. " It's a little bit concerning in a sense.. The largest earthquakes in these sequences are pretty large in size." Graham Kent is Director of Nevada Seismological Laboratory at the University of Nevada Reno. He says there have been hundreds of earthquakes southwest of Hawthorn over the past few days. The largest-- recorded at a 4.4 in size.......
In May of 1980, a strong earthquake swarm that included four Richter magnitude 6 earthquakes struck the southern margin of Long Valley Caldera associated with a 25-cm, dome-shaped uplift of the caldera floor. These events marked the onset of the latest period of caldera unrest that continues to this day. This ongoing unrest includes recurring earthquake swarms and continued dome-shaped uplift of the central section of the caldera (the resurgent dome) accompanied by changes in thermal springs and gas emissions. After the quake another road was created as an escape route. Its name at first was proposed as the "Mammoth Escape Route" but was changed to the Mammoth Scenic Route after Mammoth area businesses and land owners complained.
In 1982, the United States Geological Survey under the Volcano Hazards Program began an intensive effort to monitor and study geologic unrest in Long Valley Caldera. The goal of this effort is to provide residents and civil authorities in the area reliable information on the nature of the potential hazards posed by this unrest and timely warning of an impending volcanic eruption, should it develop. Most, perhaps all, volcanic eruptions are preceded and accompanied by geophysical and geochemical changes in the volcanic system. Common precursory indicators of volcanic activity include increased seismicity, ground deformation, and variations in the nature and rate of gas emissions.........