volcanoes

New model of Earth's interior reveals clues to hotspot volcanoes

Magikalspirit's picture

Submitted by Magikalspirit on

Space Daily- Staff Writes Sept 11 2013,Berkley CA (SPX)

This is a 3D view of the top 1,000 kilometers of the earth's mantle beneath the central Pacific showing the relationship between seismically-slow "plumes" and channels imaged in the study. Green cones on the ocean floor mark islands associated with "hotspot" volcanoes, such as Hawaii. Credit: Berkeley Seismological Laboratory, UC Berkeley.

Scientists at the University of California, Berkeley, have detected previously unknown channels of slow-moving seismic waves in Earth's upper mantle, a discovery that helps explain "hotspot volcanoes" that give birth to island chains such as Hawaii and Tahiti.

Unlike volcanoes that emerge from collision zones between tectonic plates, hotspot volcanoes form in the middle of the plates. The prevalent theory for how a mid-plate volcano forms is that a single upwelling of hot, buoyant rock rises vertically as a plume from deep within Earth's mantle the layer found between the planet's crust and core and supplies the heat to feed volcanic eruptions.

Volcanoes, lagoons, monks and cathedrals in the high Andes

Magikalspirit's picture

Submitted by Magikalspirit on

Digital Journal-By Igor I.Solar Sept 9,2013

Quipiaco is a highland lagoon usually frozen in winter surrounded by gentle hills offering breatht...

Image by Igor I Solar

Antofagasta - Among the most interesting expeditions to the Andes Mountain range is the trip to the “Salar de Tara” (Tara Salt-flats). The amazing scenery includes towering volcanoes, beautiful lagoons, incredible rock formations, and varied wildlife.

Quipiaco Lagoon

To get to ”Salar de Tara” one must travel from San Pedro de Atacama, in the region of Antofagasta in Chile, through the international route to Jama Pass which connects northern Chile with the city of Jujuy in Argentina. The route passes near Lincancabur Volcano (5,916 meters) and runs along the border between Chile and Bolivia before passing through the “Aguada de Quipiaco” (Quipiaco Lagoon). Quipiaco is a stunning highland lagoon, normally frozen in winter, surrounded by gentle hills offering breathtakingly beautiful landscapes.

 
About 50 kilometers away from the border, in the middle of the Andes highlands, the route to Tara leaves the main road to enter unmarked paths through the desert sands that are navigable only by experienced guides using 4x4, GPS-equipped vehicles.

Pakana Monks

Hotspot Volcanoes: Earthquake Risk in Hawaii

Magikalspirit's picture

Submitted by Magikalspirit on

Insurance Journal-By Khosrow Shabestari and Claire Pontbriand | September 9, 2013

hawaii_volcano

It was June 15, 1990, when Mount Pinatubo, on the island of Luzon in the Philippines, awoke from its 500-year slumber to produce the second largest volcanic eruption of the 20th century.

Nearly a year before, Luzon was shaken by a magnitude 7.8 earthquake epicentered about 60 miles northeast of the volcano. Thousands of smaller earthquakes also occurred in the months leading up to the eruption as magma moved toward the surface from more than 20 miles below the volcano. Like most volcanoes, Mount Pinatubo is located along the boundary of tectonic plates. It is here where massive pieces of the Earth’s rigid outer shell, or lithosphere, converge or diverge, producing most seismic and volcanic activity.

But volcanoes and seismic hazards exist as well in the interior of tectonic plates. The Hawaiian Islands, for example, sit well within the interior of the vast Pacific Plate. On Hawaii, earthquakes accompany the movement of magma within and under active volcanoes such as Mauna Loa, Kilauea, and Hualalai, and sometimes release the strain that accumulates along the flanks of these volcanoes.

Pages

Subscribe to RSS - volcanoes