NPS photo.
Introduction
Some chains of volcanoes lie within the interiors of tectonic plates rather than along the edges. The volcanoes are progressively older away from the largest and most active volcano. A hotspot is a large plume of hot mantle material rising from deep within the Earth. A line of volcanoes develops as a plate moves over a hotspot, much as a line of melted wax forms as a sheet of waxed paper is moved slowly over a burning candle. Several National Park Service sites lie above hotspots, or within volcanic regions formed as plates moved over a hotspot.
Hot Spot Track
AN EXPLOSION ON THE SUN: A Doomsday Machine-shaped coronal mass ejection (CME) rocketed away from the sun during the early hours of Oct. 24th: movie. It will not hit Earth. The source of the blast was a filament of magnetism near the sun’s northeastern limb, which became unstable and exploded. Solar flare alerts: SMS Text.
THE SOLAR WIND HAS ARRIVED: Bright auroras are dancing around the Arctic Circle on Oct. 24 as Earth enters a stream of high-speed solar wind. “What we are seeing right now is easily the best of the entire month,” reports Chad Blakley of Lights over Lapland.
A chain of volcanoes (hotspot track) forms as a tectonic plate moves over a plume of hot mantle material (hotspot) rising from deep within the Earth.
The landscapes of National Park Service sites along hotspot tracks differ depending on if the plate riding over the hotspot is capped by thin oceanic or thick continental crust. Oceanic Hotspots: Sites in Hawaii and American Samoa lie along chains of volcanic islands that get progressively older away from hotspots. Continental Hotspot: Yellowstone National Park contains the youngest of a chain of explosive super volcanoes that stretch across the Snake River Plain of Idaho to the Columbia Plateau in Oregon and Washington, where the Yellowstone Hotspot surfaced 17 million years ago.
NPS Landscapes Developed at Hotspots
Two prominent hotspot tracks appear on a map of the 50 United States, one involving a plate with thin oceanic crust (Hawaii), and one with thicker continental crust (Yellowstone).
Modified from “Parks and Plates: The Geology of our National Parks, Monuments and Seashores,” by Robert J. Lillie, New York, W. W. Norton and Company, 298 pp., 2005, www.amazon.com/dp/0134905172.
NPS photo.
The Hawaiian Islands are broad and high at the southeast, becoming smaller and lower to the northwest. Two national parks, Haleakala on Maui and Hawaii Volcanoes on the Big Island called Hawaii, represent different stages of passage of the Pacific Plate over the Hawaiian Hotspot. National Park of American Samoa reveals another volcanic island chain formed as the Pacific Plate moves over a different hotspot.
(Electric field and air ion exposures near high voltage overhead power lines and adult cancers) read more:
https://academic.oup.com/ije/article/49/Supplement_1/i57/5819942
Photo courtesy of Robert J. Lillie.
https://www.nps.gov/subjects/geology/plate-tectonics-hotspots.htm
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