Seven earthquakes have hit the Northwestern Pacific coast in the Oregon area, the most severe reaching 5.9 on the Richter scale. However, experts state that there are no risks of tsunami wave formation, since the earthquakes had a telluric, not tectonic character.
A String of Earthquakes
The first earthquake to shake the Oregon coast occurred on Sunday a few minutes before midnight and was measured to 5.8 on the magnitude scale. It was followed by four more quakes thru Monday. The last two seismic events occurred on Monday evening, with the magnitude of 3.9, respectively, 4.2 on the Richter scale.
This is not a rare occurrence for this area, however. Specialists from US Geological Survey explain that in this area there are crustal blocks sliding past each other in a horizontal movement. This motion creates less violent earthquakes than in other seismic areas, but the fact remains that this is an active seismic zone.
The Rep Sheet for the Seismic Oregon Coast
According to the report issued by the US Geological Survey (USGS), the Oregon coastal area was affected by 70 earthquakes with a magnitude of 5 or higher in the last 28 years. The same report indicates that hundreds of smaller magnitude earthquakes have occurred in this area in the year 2008 only.
The latest earthquakes were of a telluric nature, meaning that they were shallow, being formed at a depth of only 6 miles behind the surface. They are not related to the Cascadia – Subduction Zone fault, which could cause major earthquakes and tsunami threats. USGS seismologist Seth Moran further specified that:
“These earthquakes are happening in a totally different part of the system and aren’t really relevant in a physical way.”
There is, however, the worry that this series of shallow earthquakes may trigger a major one in the near future. There is no way to predict this occurrence, but Oregon residents are reassured for now that no tsunami wave will hit their home towns.
Image Source: Daily Mail