Costa Rica lies at the heart
of one of the most active volcanic regions on earth. The beauty
of the Costa Rican landscape has been enhanced by volcanic cones--part
of the Pacific Rim of Fire--that march the length of Central America.
Costa Rica has seven of the isthmus's 42 active volcanoes, plus
60 dormant or extinct volcanoes. Some have the look classically
associated with volcanoes--a graceful symmetrical cone rising to
a single crater. Others are sprawling, much-weathered mountains
whose once-noble summits collapsed into huge depressions, called
calderas. Still others have smooth shield-shaped outlines with rounded
tops pockmarked by tiny craters, such as on Cocos Island.
Visitors seeking to peer into the bowels of a rumbling volcano can
easily do so. The reward is a scene of awful grandeur, like the
fires of Milton's hell. Atop Poás's crater rim, for example,
you can gape down into the great well-like vent where pools of molten
lava bubble menacingly-- with diabolical, gut wrenching fumes of
chlorine and sulfur, and explosive cracks, like the sound of distant
artillery, for good effect.
Several national parks have been
created around active volcanoes, with accommodations, viewing facilities,
and lectures and guided walks to assist visitors in understanding
the processes at work. A descriptive map charting the volcanoes
is published by the Vulcanological and Seismological Observatory
of Costa Rica at the National University in Heredia, which monitors
volcanic activity throughout the nation (Libreria Lehmann and Libreria
Trejos, in San José, may sell the map).
In 1963, Irazú (elev. 3,412 meters) broke a 20-year silence
to begin disgorging great clouds of smoke and ash. The eruptions
triggered a bizarre storm which showered San José in five
inches of muddy ash and snuffed out the 1964 coffee crop, enriching
the Meseta Central for years to come. The binge lasted for two years,
then abruptly ceased. Poás (elev. 2,692 meters) has been
particularly virulent during the past 30 years. In the 1950s, the
restless four-mile-wide giant awoke with a roar after a 60-year
snooze, and it has been huffing and puffing ever since. Eruptions
then kicked up a new cone several hundred feet high. Two of Poás's
craters now slumber under blankets of vegetation (one even cradles
a lake), but the third crater belches and bubbles persistently.
In 1989, a spate of intense eruptions and gas emissions forced Poás
Volcano National Park to close (local residents were even evacuated),
and the volcano is constantly monitored for impending eruptions.
A more spectacular light-and-sound show is given by Arenal (elev.
1,624 meters). Following a four-century-long Rip van Winkle-like
dormancy, this 4,000-year-young juvenile began spouting in 1968,
when it laid a four-square-mile area to waste. Arenal's activity,
sometimes minor and sometimes not, continues unabated. Though currently
more placid, Miravalles, Turrialba, and Rincón de la Vieja,
among Costa Rica's coterie of coquettish volcanoes, also occasionally
fling fiery fountains of lava and breccia into the air.
The type of magma that fuels
most Central American volcanoes is thick, viscous, and so filled
with gases that the erupting magma often blasts violently into the
air. If it erupts in great quantity, it may leave a void within
the volcano's interior, into which the top of the mountain crumbles
to form a caldera (from the Portuguese word for caldron). Irazú
is a classic example. Irazú's top fell in eons ago. Since
then, however, small eruptions have built up three new volcanic
cones - "like a set of nesting cups," says one writer--within
the ancient caldera.
of the information on our site as it relates to Costa Rica is:
of Christopher P. Baker and Avalon Travel Publishing.
© 2004 Christopher P. Baker. All Rights Reserved.
A2Z Languages highly
recommends Christopher P. Baker's book: Moon
Handbooks Costa Rica. Click on the image to visit
his website where you can purchase this book or find out more about
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