Volcanism of Long Valley, California: The Bishop Tuff Eruption

The shield volcano is produced by the accumulation of fluid basaltic lava and exhibits the shape of a broad slightly domed structure (Pillai). Younger aged shields tend to emit fluid lava from a central vent and have sides that vary from 1 to 5 degrees (Pillai). On the other hand, older shield volcano... ... middle of paper ... ...cause_and_effect_of_volcanoes_pg2.html?cat=58>. Pillai, Maya. "Volcanic Eruptions: What Causes Volcanoes to Erupt."

After significant time, the hard lava forms a volcanic mountain. Volcanoes can form in many different sizes and shapes. They can look like a cone, have steep looking flanks, or look as if they were long cracks in the earth’s crust. (Plummer et al., 2000). If the mountain is very tall, then there is a greater chance that it was formed from past eruptions.

Mt. Mazma was created from overlapping shield and composite volcanoes during the past 400,000 years. Mount Mazma was a very active volcano to say the least with its first lavas and pyroclastic rock created 400,000 years ago followed by lava flows, lava sheets and small pyroclastic explosions creating small cinder cones, lava fields and small shield volcanoes close by. The rocks that were involved were mainly basalt, mafic andesite, andesite, dacite and in the later years rhyodacite. About 50,000 years ago is when much of the activity had calmed down with Mount Mazma.

Manmade explosions, dislocation of segments of the crust or volcanic eruptions are all triggers for an Earthquake; however, most are caused by a slippage of faults. A fault is a fracture in the Earths crust along which two blocks of the crust have slipped within one another. These faults are grouped into three categories (normal, thrust and strike-slip) and are located all over the Earth. In North America there is a very large fault that runs through California that separates the North American plate and the Pacific plate. The afore mentioned fault is called the San Andreas fault and is approximately 1300 kilometers long and a great source for Earthquakes and activity.

Accomplishing this daunting task will ensure that in the future when an eruption occurs, the population at risk will be prepared and lives can be saved. Numerous methods are available for monitoring volcanic activity, and scientists typically synthesize data and observations from all methods available in order to obtain the most comprehensive look at the area being observed. One frequently used technique is monitoring seismic activity that may indicate flow of magma and gas beneath the surface. As magma at extreme temperatures of sometimes over one thousand Degrees Celsius rises through cracks in the Earth's crust, the intense temperature and pressure causes the surrounding rock to crack, as illustrated in the diagram above. This brittle fracture of the surrounding rock often causes earthquakes or vibrations called tremors.

Due to this curve of the islands the area is broken into two areas known as the “northwestern (leeward) islands” and the “southeastern (windward) islands.” The existence of islands of Hawaii is due to the claimed “hot spot” that began form... ... middle of paper ... ..., M. (2006). "Growth and Collapse of Hawaiian Volcanoes." J.Volcanol.Geotherm.Res., 151(1),. Lipman, P. (2011). "Early Growth of Kohala Volcano and Formation of Long Hawaiian Rift Zones."

There are also more explosive volcanic eruptions in which the gas pressure builds until it is extremely high and the viscuous lava can no longer stand i... ... middle of paper ... ...because these volcanoes are located in different areas of the world or because El Nino occured during the year of the eruption of El Chichon. All of these evidences are still being compiled and scrutinized in order to verify the true relation between volcanic eruptions and climate change. Works Cited: Angell, James. "Stratospheric Warming Following Volcanic Eruptions." http://capita.wustl.edu "The Effects of Volcanic Eruptions on Earth's Climate."

The volcano erupts over and over again if it stays active. As those layers build up the volcano grows and it becomes ginormous. This process takes thousands of years! A volcano is formed when the plates in the Earth’s crust moves. There are giant plates under the surface of the Earth or the crust.

There are thirty domes that formed together (Molossia;2004). They were originally formed by the intrusion of a dike. About six hundred years ago when the magma began rising in the southern end of the Mono-Inyo Craters there was a series of eruptions and ground cracking. The dike was spreading both hor... ... middle of paper ... ...is Panum Crater that is six hundred and forty years old (Topinka:2001). (Picture below compliments of USGS).

Earthquakes generally happen around magma body intrusions from the raised heat and pressure triggering acoustic vibrations. By plotting long-period waveforms points of origin, we can get a picture of the size and depth of the magma body. Research points to the existence of a horizontal crack at 150 m near the Halemaumau crater, a pit located within the summit caldera of Kilauea. This crack caused by leaking gases raised the overall hydrothermal pressure and caused a rapid increase of volcanic fluid ( Kumagai, Hiroyuki, Bernard A. Chouet, and Phillip B. Dawson 2005). Long-period seismicity has enhanced our understanding of volcanoes hydrothermal structure.