|
Poás
Volcano National Park
Like the other volcanoes in the Central Volcanic Cordillera, the silhouette
of Poás Volcano as seen from the Central Valley gives no hint of the power
and pent-up fury below the surface. But once at the summit and standing on the
crater's rim, it becomes easier to understand the forces that have shaped this
region of the planet.
With a diameter of 1.5 km., the active crater is reportedly the widest of any
volcano in the world. If it is clear enough to see to the bottom of the
300-meter deep crater, you will surely observe some type of activity ranging
from fumaroles to bubbling emissions on the surface of the small rain-filled
lake to actual geyser-type eruptions, but it is constantly changing. During
the early 1990s, there was enough geyser activity to cause the lake to lose
its water by the end of the dry season (April/May); this resulted in increased
gaseous emanations that forced the park to close on a few occasions.
Looking to the left of the crater you can see the deleterious effects of the
volcanic gases that cause a localized form of acid rain. For several
kilometers downwind from the crater the vegetation is brown and dying. On
exceptionally clear days you can see the top of Arenal Volcano (60 km.
distant) by looking in this direction. If you keep your eye on it long enough,
you may be able to see the cloud of ash that accompanies an eruption.
A few meters back down the trail from the active crater overlook, a 1.5 km.
trail leads off to Lake Botos, a densely forested dormant crater filled with
rain water. A portion of this trail goes through an eerie-looking section of
stunted forest. The trunks and branches of the small trees here are gnarled
and twisted from the harsh climatic conditions in exposed areas at high
elevations. At the Lake Botos overlook you'll be near the highest point in the
park which is 2,704 meters.
At this elevation wildlife is not particularly abundant, but there is usually
a fair amount of bird activity. Some of the more common species are the
Fiery-throated Hummingbird, Sooty-capped Bush-Tanager, Slaty Flowerpiercer,
Mountain Eleania, Black-billed Nightingale-Thrush, and Black-and-yellow
Silky-Flycatcher.
Given its high visitation, the National Park Service has chosen Poás as a
model park. One of the benefits of this is the Visitors' Center which presents
a thorough explanation of volcanism and the natural history of Poás using a
variety of entertaining and informative displays.
Getting there: From San José, drive to the town of Alajuela. Coming in from
the airport will put you on calle 2, take this street all the way through town
and follow it (Rt. 130) to Itiquis and Fraijanes, following the signs for the
volcano.
As it only takes 90 minutes to drive the paved road to the volcano's summit,
this national park receives more visitors than any other. On weekends and
holidays it is very popular with local citizens as a picnic spot.
Climate: It can get cool at this 2,500+ meter elevation, so layers are
advised. If it is sunny, use plenty of sunscreen because the thinner air lets
the UV rays through even more intensely than if you were at the beach.
Mornings tend to be clear, but the clouds can build up quickly. The driest
months are from January to April.
History: Written accounts of Poás only date back to 1828, and the first
mention of volcanic activity is from 1834. Between then and the present there
have been four other periods of eruptive activity, the most recent one lasting
from 1952-54. The largest of any of these relatively recent eruptions was in
1910 when an immense column of smoke and ash issued from the crater. The
fallout from this eruption has been estimated to have been nearly
three-quarters of a million tons of ash.
In a way, we have Poás Volcano and the Great Smoky Mountains in Tennessee to
thank for Costa Rica's extraordinary National Park system. On a visit he made
to the U.S. in the 1960's, Park Service founder, Mario Boza, was so impressed
with the Great Smokies that upon returning to Costa Rica he drew up a
management plan for Poás Volcano as if it were a national park. This, his
masters thesis, was the start of what would become perhaps the most ambitious
system of national parks and refuges anywhere in the world.
|
