Essay On Mount Hood

Web Project 2 http://pubs.usgs.gov/fs/2000/fs060-00/ The most recent significant eruption of Mount Hood happened in the 1790’s shortly before Lewis & Clark passed through the area. There was less significant explosive activity around the middle of the 17ths century. After this time the volcano has been quiet and inactive. There will come a time when Mount Hood will erupt again. How will those eruptions impact us and what might they look like? Through study of Mount Hood’s past volcanic behavior U.S. Geological Survey (USGS) scientists are able to predict and prepare for future eruptions and activity in the area. Mount Hood is more than a half a million years old. The volcano has had a long history of eruptions through the centuries however, there have been two significant periods of time with eruptive behavior dating back 1500, and 200 years in the recent past. Mount Hood’s history is less violent or explosive than Mount St. Helen’s to the North. Characterized by four distinct volcanic behaviors, Mount Hood experiences lava flows traveling short distances in most cases less than six to eight miles from the source. These flows build up flanks one sector of the volcano at a time. At times the lava doesn’t flow but instead builds domes that can reach hundreds of feet in height. Repeatedly collapsing lava domes are responsible for …show more content…
The biggest among these caused the removal of large sections of the flanks of the volcano and even the summit itself. The devastating results where lahars flowing all the way into the Colombia river. Occasionally large debris avalanches are triggered by volcanic activity. However smaller ones occur much more often and are not triggered by volcanic activity. Avalanches of smaller size happen when rocks fail spontaneously due to rocks being altered and weakened by acidic solutions or weather based erosion caused by cycles of freezing and