mt. rainier last had a significant eruption in ad 79.
when did mt. rainier last have a significant eruption?
ad 79
pierce county is notable for being home to mount rainier, the tallest mountain and a volcano in the cascade range. its most recent recorded eruption was between 1820 and 1854. there is no imminent risk of eruption, but geologists expect that the volcano will erupt again. if this should happen, parts of pierce county and the puyallup valley would be at risk from lahars, lava, or pyroclastic flows. the mount rainier volcano lahar warning system was established in 1998 to assist in the evacuation of the puyallup river valley in case of eruption.





















































section::::geography.
pierce county, washington
like other volcanoes in the garibaldi belt, mount fee is not monitored closely enough by the geological survey of canada to ascertain how active its magma chamber is. this is partly because no major eruptions have taken place in canada for over a hundred years and the volcano is located in a remote region. as a result, volcano monitoring is less important than dealing with other natural processes, such as tsunamis, earthquakes and landslides. no recent earthquakes are known to have occurred at mount fee. if it were to erupt there would likely be weeks, months or years of warning signs, such as clusters of minor earthquakes that would likely originate less than below the surface. they are generally too small to be felt by people, but the existing network of seismographs has been established to monitor tectonic earthquakes. however, the seismograph network is too far away to provide a good indication of what is happening under the mountain. it may sense an increase in seismic activity if the volcano becomes very restless, but this may only provide a warning for a significant eruption. it might detect activity only once the volcano has started erupting. a significant eruption at mount fee would probably have considerable effects, particularly in a region like southwestern british columbia where the garibaldi belt is located in a highly populated area. because of these concerns, significant support from canadian university scientists has resulted in the construction of a baseline of knowledge on the state of the garibaldi volcanoes.
mount fee