By ExploreNow Editor, on May 19th, 2012%
Volcano Type: Complex volcano
Volcano Status: Historical
Last Known Eruption: 2010 (continuing)
Summit Elevation: 2552 m 8,373 feet
Latitude: 14.381°N 14°22’51″N
Longitude: 90.601°W 90°36’4″W
Eruptions from Pacaya, one of Guatemala’s most active volcanoes, are frequently visible from Guatemala City, the nation’s capital. Pacaya is a complex basaltic volcano constructed just outside the southern topographic rim of the 14 x 16 km Pleistocene Amatitlán caldera. A cluster of dacitic lava domes occupies the southern caldera floor. The post-caldera Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. A subsidiary crater, Cerro Chino, was constructed on the NW somma rim and was last active in the 19th century. During the past several decades, activity at Pacaya has consisted of frequent strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and armored the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit of the cone.
 Pacaya's violent eruption Click Here For The Rest Of Pacaya, Guatemala
Originally posted 2010-08-30 04:18:23.
By ExploreNow Editor, on May 14th, 2012%
Volcano Type: Caldera
Volcano Status: Historical
Last Known Eruption: 1931
Summit Elevation: 1341 m 4,400 feet
Latitude: 56.88°N 56°53’0″N
Longitude: 158.17°W 158°10’0″W
One of the most dramatic calderas of the Aleutian arc, the 10-km-wide Aniakchak caldera was formed around 3400 years ago during a voluminous eruption in which pyroclastic flows traveled more than 50 km north to the Bering Sea and also reached the Pacific Ocean to the south. At least 40 explosive eruptions have been documented from Aniakchak during the past 10,000 years, making it the most active volcano of the eastern Aleutian arc. A dominantly andesitic pre-caldera volcano was constructed above basement Mesozoic and Tertiary sedimentary rocks that are exposed in the caldera walls to elevations of about 610 m. The ice-free caldera floor contains many pyroclastic cones, tuff cones, maars, and lava domes. Surprise Lake on the NE side drains through The Gates, a steep-walled breach on the east side of the 1-km-high caldera rim. Vent Mountain and Half Cone are two long-lived vents on the south-central and NW caldera floor, respectively. The first and only confirmed historical eruption took place in 1931 from vents on the west and SW caldera floor. Click Here For The Rest Of Aniakchak, Alaska
Originally posted 2010-08-25 03:51:13.
By Volcano Explorer, on May 11th, 2012%
 Dotsero Volcano Type: Maar
Volcano Status: Radiocarbon
Last Known Eruption: 2200 BC ± 300 years
Summit Elevation: 2230 m 7,316 feet
Latitude: 39.661°N 39°39’38″N
Longitude: 107.035°W 107°2’6″W
Dotsero is a 700-meter (2,300 ft) wide by 400-meter (1,300 ft) deep maar volcano located in Dotsero, Colorado near the junction of the Colorado River and the Eagle River. It is classified as a scoria cone with evaporitic rock, basaltic tephra, and oxidized sandstone. Erupting approximately 4200 years ago, it is the youngest volcano in Colorado. It is currently dormant. Click Here For The Rest Of Dotsero, Colorado, USA
Originally posted 2011-06-10 19:30:47.
By ExploreNow Editor, on May 9th, 2012%
Turrialba, (3,340 meters) the southeast-most of Costa Rica’s Holocene volcanoes, is a large vegetation-covered stratovolcano located to the northeast of Irazu volcano. Three well-defined craters occur at the upper end of a broad summit depression that is breached to the northeast. Turrialba has been quiescent since a series of explosive eruptions in the 19th century that were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the summit craters.
 Turrialba Volcano  Turrialba Crater  Turrialba Cone Turrialba, the easternmost of Costa Rica’s Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive 3340-m-high Turrialba is exceeded in height only by Irazú, covers an area of 500 sq km, and is one of Costa Rica’s most voluminous volcanoes. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m wide summit depression that is breached to the NE. Most activity at Turrialba originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred at Turrialba during the past 3500 years. A series of explosive eruptions during the 19th century were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.
 Turrialba Volcano The summit crater complex of Turrialba volcano is seen here from the north, with the Central Valley of Costa Rica in the background. Three well-defined craters can be seen at the upper SW end of a broad 800 x 2200 m wide summit depression that is breached to the NE. Turrialba has been quiescent since a series of explosive eruptions during the 19th century that were sometimes accompanied by pyroclastic flows. Hydrothermally altered ground can be seen at the central and SW summit craters (right), where fumarolic activity continues.
 Caldera of Turrialba Volcano  Turrialba Volcano (Andre Quiros)  Turrialba Volcano (Andre Quiros) Originally posted 2010-07-06 11:04:15.
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