The west coast of North America has been tectonically and volcanically active for billions of years. The Sierra Nevada Mountains in eastern California were born of volcanoes, and magma has been erupting in the Long Valley to the east of the mountains for over three million years (Bailey, et. al., 1989). However, the climactic eruption of the region occurred relatively recently in the region's geologic history. About 760,000 years ago, a huge explosion of magma warped the Eastern Sierra into the landscape that exists today. The eruption depleted a massive magma chamber below the earth's surface so that the ceiling of the chamber imploded, forming what is now known as
Mt. Rainier was formed not in one great cataclysm, but by many years of volcanic activity. It is a composite volcano made from sluggish intermittent lava flows and explosive eruptions of ash and rock. Volcanoes have
Volcanoes are one of the most intimidating natural processes that occur on this planet. Usually they are associated with danger and chaos. Volcanoes are characterized by both their composition and eruption types. In this paper we will be exploring the similarities and differences between three infamous volcanoes, Mt. St. Helens, Mt. Kileaue, and the currently relevant Mt. Agung.
Mount St Helens erupted on the 18th May 1980 at 9am and is an active strata volcano Washington State USA, a MEDC. Where as on 18th July 1995, during the daytime, Montserrat, a LEDC during the day, Montserrat's Soufrière Hills composite volcano of a height 1050m, meaning sulphur hills, dormant for centuries, erupted and produced a phreatic eruption. The volcano is a strata volcano also. Mount St. Helens is a composite volcano which lies near to a destructive plate boundary where the small Juan de Fuca Plate is being subducted underneath the North American Plate where as the eruption
Lava flows of rhyolite and basalt have flowed through parts of Yellowstone as recently as 70,000 years ago. These lava flows destroyed everything in their paths while moving slowly at a rate of a few hundred feet per day, flowing months, or sometimes even several years. They are thick and cover as much as 130 square miles. They have nearly filled the Yellowstone Caldera, and spilled beyond the caldera’s border. These lava flows are responsible for forming four of the nine named plateaus in
Mount St. Helens Location: Washington, United States Latitude: 46.20 N Longitude: 122.18 W height: 2,549 meters or 8,364 feet - 9,677 feet before May 18, 1980 Type: Stratovolcano Number of eruptions in past 200 years: 2-3 Latest Eruptions: Between 1660-1700, around 1800-1802, 1831, 1835, 1842-1844, 1847-1854, 1857, 1980-? Present thermal activity: strong steaming Nickname: Mount Fuji of the West Remarks: continuous intermittent activity since 1980 with occasional eruptions of steam and ash; occasional pyroclastic flows; intermittent dome forming. MSH is considered a young volcano that developed over the last 40,000 years and is one of the most active volcanoes in the Cascade Range. Geologists predicted that the
Imagine a single event that can kill 57 people and 7000 deer and elk. Snap trees like a toothpick, and turn the sky grey for 15 days. Now, stop imagining, Mount St. Helens, in the Cascade Range of southwestern Washington State, erupted. On May 18th,1980. According to (Campbell 371), “At least $1 billion in economic damage was reported”. The eruption of Mount St. Helens took many lives, and devastated America. Mount St. Helens destroyed more than 230 square miles of ancient forest.
Anpother factor that can have an impact on the level of hazard posed by a volcano is the type of plate margin on which it occurs. Volcanoes occuring at constructive plate boundaries are usually much less violent than those occuring at destructive plate boundaries. This is because the magma produced by plates moving apart is Basic, and therefoe has a low viscosity, allowing it to flow easily. The lava is produced from a central vent or fissure and erupts regularly but not usually violently. Also,constructive plate boundaries are often found under the sea and create submarine volcanoes, such as along the Mid-Atalntic ridge, so pose few threats to humans. As a result, the hazards posed by volcanoes at constructive plat eboundaries is relatively low. However, the subduction of one plate under another at destrctive plat eboundaries can form an acidic magma chamber, due to the build up of intense heat. Acidic magma is very viscous and resisitant to flow, meaning that there is often a huge build up of pressure, which can result in very violent and dangerous eruptions involving ash and pyroclastic flow. This can pose a a serious hazard. Pyroclastic flowsa are extremely dense, containing toxic gases at very high temperatures, and can move at speeds over 100km/h. The consequences of such an unpredictable hazard can be extremely seruous
The town of Orting is built in the valley of Mount Rainer in western Washington. Located 30 miles from the volcano, Orting is built upon deposits of 500 year old lahar erupted from the volcano. Mount Rainier is an active stratovolcano of andesitic rock, located along the convergent plate boundary where the North American Plate and the Pacific Plate meet. Mount Rainier is the most prominent mountain in the contiguous United States and is approximately 500,000 years old (The Cardinal). Although Mount Rainier is considered to be an active volcano because of its lahar flow, it is currently in resting state. The last eruption of this massive volcano occurred more than 115 years ago in 1884.
These species of wildflowers include american bistort, lupine, paintbrush, pasqueflower, gray’s lovage, avalanche lily, and glacier lily. Mount Rainier was formed by years and years of volcanic activity. Roughly 500,000 years ago lava and pumice began to ooze from beneath the crust producing a cone that was about 16,000 ft high. 494,300 year later Mount Rainier violently erupted and collapsed causing mud and debris flow. The last eruption of Mount Rainier occurred 150 years ago. These eruptions produced volcanic ash, lava flows, and avalanches. The lahars damaged vegetation but overtime made the soil fertile which then produced new extensive vegetation. The volcanic ash also negatively affected animal respiratory systems, eyes, and skin. Scientists have not estimated an exact date of the next large eruption of Mount Rainier but they predict similar eruptions and sporadic releases s of steam and ash resulting in mudflow and floods. In conclusion, Mount Rainier is one of the most dangerous volcanoes in the United States and there is no telling when or how destructive and effective it’s next eruption will
The Island of Hawaii sits on (almost in the middle of) the Pacific Plate. The Pacific Plate is a giant jigsaw piece of the Earth’s crust that is slowly moving in a northwesterly direction. It moves about four inches a year. There is a basically stationary hot spot deep within the Earth’s mantle. Heat from this hot spot makes molten lava and rock (magma) that rises through the Pacific Plate and erupts continuously on the ocean floor. After thousands of eruptions and over many many years, an island forms a rocky
Volcanoes can be found throughout the entire world and are formed when there is a rupture in the mantle of the Earth's crust. This effect allows the output of volcanic lava, ash, and various types of gases. These tectonic plate breaks are normal, the planet Earth is divided into 17 tectonic plates and consistently move against each other forming shifts from low to high intensity. It can cause displacement of earth or water.
Cenozoic sedimentary rocks predominated to the west and east of the central mountain while plutonic rocks predominated in the peninsular ranges. The irregular contact between these geologic regions reflects the ancient topography of the area. The ancient oceanic crustal plate created an archipelago of a volcanic island. The former's subduction created immense volumes of magma. This resulted to the congealation of plutonic rock in the crust. The local rocks that existed before the tectonic forces uplifted, and erosion capped the deeply buried plutonic rocks that formed a steep and rugged mountains coastline, similar to that present one, which in the west coast of south America.
Mt St Helens (or the Fuji-san of America) is known for the May 18th, 1980 eruption which destroyed the whole north side of the volcano in just a few minutes within a 6 mile radius. Mount St Helens is named by George Vancouver after a British Diplomat nicknamed Baron St Helens. Mt St Helens is located in Yakima, Washington State, United States, North America on the North American tectonic plate. (Which is a continental plate) Yakima, Washington is almost right in the middle of the state, but Washington borders British Columbia and Alberta, Canada and Idaho and Oregon, United States, and of course, the Pacific Ocean.