Lassen Volcanic National Park History Geology And Geography

The area surrounding Lassen Peak is still active with boiling mud pots, stinking fumaroles, and churning hot springs. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcano can be found (plug dome, shield, cinder cone, and strato).

1 History

From 1850- 1851 wittinesses reported seeing ash, steam, and ejected volcanic cinders in the area of Cinder ConeCinder Cone is a cinder cone volcano in Lassen Volcanic National Park. Within the park it is located about 10 miles northeast of Lassen Peak and provides a magnificent view of Brokeoff Mountain, Lassen Peak, and Chaos Crags. Cinder Cone was probably creat. For many years these eruptions were attributed to Cinder Cone, but more recent geologic studies of the volcano indicate that it last erupted much earlier.

Lassen Peak and Cinder Cone were declared United States National Monuments in 1907Events January events January 6 Maria Montessori opens her first school and daycare center for working class children in Rome Casa dei Bambini in San Lorenzo). January 14 An earthquake in Kingston, Jamaica kills more than a 1,000 January 23 Charles Curtis by President Theodore RooseveltTheodore Roosevelt Order 26th President Term of Office September 14, 1901 March 4, 1909 Predecessor William McKinley Successor William Howard Taft Date of Birth Wednesday, October 27, 1858 Place of Birth New York City Date of Death Monday, January 6, 1919.

Starting in May 1914Events January 4 77 seal hunters freeze to death on ice near Labrador January 5 Ford Motor Company announces an eight-hour workday and a minimum wage of $5 for a day's labor February 13 Copyright: In New York City the ASCAP (for American Society of Compos and lasting until 1921Events January 2 The first religious radio broadcast ( KDKA AM in Pittsburgh, Pennsylvania) January 2 Spanish liner Santa Isabel sinks off Villa Garcia 244 dead January 2 DeYoung Museum in Golden Gate Park San Francisco opens. January 20 Republic of Turke, a series of minor to major eruptions occurred on Lassen. These events created a new crater, and released lavaLava is molten rock that a volcano expels during an eruption. Due to its high temperature, lava can be quite fluid when first exuded from a volcanic vent, but eventually solidifies into rock. However, the lava may flow many miles before solidification. and a great deal of ashAsh is: The solid residue left after something has burned, usually wood and plant material (such as tobacco). It consists mainly of carbonates and bicarbonates of metals in the original organic material the metals that primarily compose the ash of the ana. Amid this volcanic activity, Lassen Volcanic National Park was created on August 9, 1916.

In 1974 the United States Park Service took the advice of the USGS and closed the visitor center and accommodations at Manzanita Lake . The Survey stated that these buildings would be in the way of a rockslide from Chaos Crags if an earthquake or eruption occurred in the area. An aging seismograph station remains.

2 Geology and geography

Main article: Geology of the Lassen area

The heat that fuels the volcanoes in the park is derived from subduction off the coast of Northern California

Lassen Peak is made of dacite and is the world's largest volcanic dome . The volcano sits on the north-east flank of the remains of Mount Tehama, a stratovolcano that was a thousand feet higher than Lassen and 11 to 15 miles wide at its base. After emptying its throat and partially doing the same to its magma chamber in a series of eruptions, Tehama collapsed into itself and formed a two-mile wide caldera in the late Pleistocene. Since that time the remains of Tehama have been heavily eroded.

On the other side of the present caldera is Brokeoff Mountain (9235 feet), which is an erosional remnant of Mount Tehama and the second highest peak in the park. Mount Conrad, Mount Diller, and Pilot Pinnacle are also remnant peaks around the caldera.

Sulphur Works is a geothermal area in between Lassen Peak and Brokeoff Mountain that is thought to mark an area near the center of Tehama's now-gone cone. Other geothermal areas in the caldera are Little Hot Springs Valley, Diamond Point (an old lava conduit), and Bumpass Hell (see Geothermal areas in Lassen Volcanic National Park).

Cinder Cone, located about 10 miles northeast of Lassen Peak, is a cinder cone volcano that was probably created in two eruptions of ash and volcanic cinders in the 1850s. It was made inactive by a series of basalt lava flows that created the Fantastic Lava Beds.

There are four shield volcanoes in the park; Mount Harkness (southwest corner of the park), Red Mountain (at south-central boundary), Prospect Peak (in northwest corner), and Raker Peak (north of Lassen Peak). All of these volcanoes are 7000-8400 feet above sea level and each are topped by cinder cone volcanoes.

During ice ages, glaciers have modified and helped to erode the older volcanoes in the park. The center of snow accumulation and therefore ice radiation was Lassen Peak, Red Mountain, and Raker Peak. These volcanoes thus show more glacial scarring than other volcanoes in the park.

3 Reference

Geology of National Parks: Fifth Edition, Ann G. Harris, Esther Tuttle, Sherwood D., Tuttle (Iowa, Kendall/Hunt Publishing; 1997) BooksEnthsiast.com

4 External link

National parks of the United States California geography National parks in California Shasta County, California

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