Courtesy Juan Carlos Diago, 1995 (Bernardo Pulgarín, INGEOMINAS, Colombia).Nevado del Huila, a volcano in Columbia, erupted shortly before midnight on Monday forcing about 3,500 people to evacuate. The eruption was preceded by seismic activity that started on April 8.
Before this recent activity, Nevado del Huila had been quiet since the 16th century.
In 1985 25,000 people were killed when another Columbian volcano, Nevado del Ruiz, erupted initiating a series of deadly lahars.
Jabal at-Tair, a small island formed entirely by a volcano was thought to be dormant until yesterday. But following several days of small earthquakes it erupted last night, September 30th at 7pm spewing lava and ash into the air at great heights.
Sadly it appears that several soldiers based on the island have died in the eruption although the number of people hurt is not immediately clear.
The volcanism that created the island is the result of two continental plates, Africa and Arabia, rifting apart from each other with the Arabian Plate (Saudi Arabia, Yemen, and more) moving away to the northeast. While this rifting is pretty old, beginning about 540 million years ago, the Red Sea only started to form about 55 million years ago. The Red Sea is widening at a rate of about .6 inches a year which accounts for the volcanic activity that we see there now.
More on the Red Sea's geologic history.
11,000 people have been evacuated from the area surrounding Mount Merapi, as lava and superheated gas poured from the volcano. (This is the same area affected by last week's major earthquake.) Merapi is one of the world's most active and unpredictable volcanos, and some scientists have suggested that the earthquake contributed to this latest round of volcanic activity.
The stratovolcano Augustine is located in south central coastal Alaska, forming a circular island about 1,260 meters in height. Augustine has been erupting since January 2006, and is now color-coded “orange,” meaning further eruptions can occur at any time. Lava flow and rock falls are likely to continue for several weeks or months. The geologic record at Augustine indicates the volcano has been active for about 40,000 years. It experienced a very large eruption in 1883 that blew most of the volcano away, and has been rebuilding itself ever since. In 1986, it erupted and created an ash cloud over Anchorage, some 290 km away. Satellites actively monitor Augustine for changes in temperature and ash plumes. Check out this live web cam of the volcano.
In addition to volcanoes on the west coast of the continental U.S., there are over forty-one historically active volcanoes in Alaska, including thirty that are monitored in real time. Most of Alaska’s volcanic features fall along the Aleutian arc. These volcanoes form a neat line between Alaska and Russia because they fall along a plate boundary. The subduction of the Pacific Plate beneath the overlying North American plate is what creates these volcanoes—and multiple earthquakes as well!
No humans live close enough to Augustine to be threatened by eruptions. Ash clouds from the volcano, however, do pose a threat to air travel in the region. Volcanic ash not only makes it difficult to navigate; it can also damage moving parts of jet planes, cause clogs, and even trigger engine failure. Although no human life has been lost, many planes in the last two decades have suffered damage from volcanic ash while flying through the region.
Saturn's moon Titan is the only satellite (moon) in our solar system that has a dense atmosphere. Nitrogen is the main component of this atmosphere and methane the second most important. The Cassini spacecraft photographed Titan as it passed by on October 26, 2004. Later analyses of the images revealed a cryovolcano that spews ice instead of lava. This finding is reported by Christopher Sotin and associates at Universite de Nantes and the Universite de Paris-Sud in France and other institutions in Germany, Italy, and the USA (Arizona, California, Colorado, New York, Washington). This giant ice volcano may also release methane into the atmosphere; however, the images show that a widespread methane ocean does not exist. Because Titan's atmosphere is similar to that of Earth, scientists are studying Titan for clues to the origin of life.