Page 134 - Volcano and Geothermal Tourism

Case Study 5

Yellowstone National Park,

Wyoming

Malcolm Cooper the Red Mountains, about 60km to the south, are
joined by the volcanic arc of the Absaroka mountains
Introduction east of Yellowstone Lake. The age of the rocks
forming this complex ranges from 70,000 years or
Established in 1872, Yellowstone National Park less to two million years old. The main landscape-
was America’s first national park. Located in the forming events were a series of three caldera
states of Wyoming, Montana and Idaho, it is home producing eruptions dating from 2.1 million years
to a large variety of wildlife and to the world’s to 600,000 years ago that produced about 6669km
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greatest output of geothermal water (Figure CS5.1). of rhyolite (in comparison Mt St Helens produced
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The park covers an area of nearly 9065km in the about 1.04km ). Since then three further eruptive
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north-west of Wyoming and contains the largest pulses about 150,000, 110,000 and 70,000 years ago
concentration of geothermal features in the world produced about 1000km of rhyolite (Decker and
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(Rhinehart, 1980), with around 100 different hot Decker, 2007; Yellowstone National Park, n.d).
springs groups totalling over 10,000 individual The geothermal activity that produced this
thermal features (Bryan, 1986). The distribution of landscape is today expressed in the form of hot
its thermal features is controlled by regional fault springs, geysers, boiling mud pools and travertine
systems and the Yellowstone Caldera (Eaton et al, terraces, although the volcanic caldera remains on
1975; White et al, 1988). The terraced Mammoth the active list since earthquake and other geologic
hot springs are an example of the travertine hot data indicate that magma is close to the surface in
spring type, with over 100 hot springs cascading this area (the Yellowstone ‘Hot Spot’; Decker and
over a number of travertine terraces (Bargar and Decker, 2007, pp197–198). Yellowstone National
Muffler, 1975) and are one of the most popular Park contains an estimated 10,000 thermal features.
tourist attractions in the park.
Of these 3 per cent are geysers, and the rest are
steaming pools, hissing fumaroles, bubbling mud pots
Geophysical aspects and or warm seeps. Most of Yellowstone’s geysers are
small but six erupt 30m or higher on a predictable
history of activity daily basis. Old Faithful, the most famous of these,
The Yellowstone National Park comprises primarily erupts approximately every 45 to 90 minutes.
high, forested, volcanic plateaus that have been
eroded by glaciation and stream flows, and that are Risk factors
flanked on the north, east and south by mountains. While there may be little risk from an actual
Its elevation averages 2400m, ranging from 1600m eruption at Yellowstone at present there remain
in the north, where the Gardner River drains from many risky elements to visiting this park. First and
the park, to 4000m in the east at the summit of foremost are of course the hot springs and mud
Eagle Peak in the Absaroka range. The Washburn pools themselves. At temperatures over boiling
range is made of debris flows preserved in the north point they are of course not to be entered. There
flank of an old dissected volcano. This volcano and is also the risk to the formations of travertine and

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