Volcano Watch — How to watch world volcanoes on the web

The volcanoes getting the most attention now are El Hierro in the Canary Islands northwest of mainland Africa, Mount Etna on the Italian Island of Sicily, and Nyamuragira volcano in the Congo. You can keep up with world volcanism here—http://www.volcano.si.edu/reports/usgs.

The Canary Islands, like Hawai‘i, are the tips of a chain of volcanoes on the Atlantic ocean floor west of the African country of Morocco. Like the Hawaiian Islands, they are thought to be produced by a mantle hotspot.

El Hierro, the volcano associated with the southwestern-most island, has recently erupted through a series of submarine vents offshore of the southernmost town of La Restinga. Toward the end of September, Spanish authorities evacuated that end of the island. So far, the eruption has produced discolored sea water that can be seen from space via satellite, some floating and steaming rocks, gases, and thousands of earthquakes—the largest being a magnitude-4.3 in early November. Activity has waxed and waned and it is currently quiet.

The El Hierro eruption is being monitoring by the Instituto Geografico Nacional (http://www.01.ign.es/ign/layout/volcaVolcanologia.do) and their results are reported in Spanish. If you don't read Spanish, you can use the Google Chrome internet browser which will do a very credible job of translation. Current earthquake and other geophysical activity can be tracked on their website. You can watch the activity (or lack thereof) at http://earthquake-report.com/2011/11/12/32535.

Mount Etna, on the Italian Island of Sicily, has erupted 18 times this year. The most recent episode was in mid-November and was very similar to many of the past events—llava fountains, ash emissions that closed the nearby Catania airport, and a 4 km-long (2.5 mi) lava flow in a couple of hours of activity. Etna, and several other nearby volcanoes, is being very closely monitored by the Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione di Catania and their website has lots of data, photos, webcams, and background information—http://www.ct.ingv.it.

The summit and flanks of Mount Etna are protected with the Parco dell'Etna (http://www.parks.it/parco.etna/index.php) which offers information and education about the surrounding area. Tourists can engage guides or join one of many tours to the summit for a safe trip between eruptions.

Possibly the most spectacular of the currently erupting volcanoes (outside of Hawai‘i) is Nyamuragira in the Central African country of The Congo. On November 6, a fissure eruption started on the northern flank of the 3,058 m (10,032 ft) high volcano with 300 m (1,000 ft) lava fountains and a lava flow moving through unpopulated areas to the north within Virunga National Park. The most recent information (November 18) suggests that the lava flow had advanced nearly 12 km (7.5 mi) before stalling but lava fountains were still active at the flow’s source.

The Virunga National Park system is probably better known for its population of endangered mountain gorillas, as well as chimpanzees, elephants, and buffalos. Park rangers are normally busy protecting the wildlife from poachers and the park from numerous illegal activities and have set up a webpage reporting on the effect of the eruption on the gorillas and chimps—http://gorillacd.org/2011/11/18/gorillas-and-volcanoes/ (Webpage no longer available).

The park is concerned about humans, too. When the Nyamuragira eruption started, rangers quickly set up a camp at a location safe for visitors and started offering a trip for volcano tourists. For $300, park rangers will pick you up in the town of Goma and, after an hour's drive, hike with you 3 to 4 hours to the camp. You can spend the night one mile south of the erupting vent before beginning the journey back to Goma the next day.

Back at home, Kīlauea's continuous activity has wooed international eyes through the internet this year resulting in thousands of webpage hits to our website and webcams at http://hvo.wr.usgs.gov. Hawai‘i Volcanoes National Park protects visitors as well as endangered birds and plants and has hosted most of the volcanic activity.

And that's it for armchair volcano watching on this Thanksgiving weekend!

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Volcano Activity Update

A lava lake was present within the Halema‘uma‘u Overlook vent over the past week, resulting in night-time glow that was visible from the Jaggar Museum overlook. The lake, which is about 100 m (330 ft) below the floor of Halema‘uma‘u and visible by Webcam, rose and fell slightly during the week in response to back-to-back deflation-inflation cycles.

Eruptive activity on Kīlauea's east rift zone was restricted to surface flows about 5.5 km (3.4 miles) southeast of Pu‘u ‘Ō‘ō and a few short flows on the Pu‘u ‘Ō‘ō crater floor. The short flows were intermittent while the more distant flows traveled through a lava tube that is fed by the September 21 fissure on the upper east flank of the Pu‘u ‘Ō‘ō cone.

Four earthquakes beneath Hawai‘i Island were reported felt this past week. A magnitude-2.6 earthquake occurred at 6:17 p.m., HST, on Thursday, November 17, 2011, and was located 4 km (2 mi) north of Captain Cook at a depth of 11 km (7 mi). A magnitude-2.8 earthquake occurred at 3:06 p.m. on Friday, November 18, and was located 15 km (9 mi) northwest of Nā‘ālehu at a depth of 5 km (3 mi). A magnitude-4.0 earthquake occurred at 10:17 a.m. on Sunday, November 20, and was located 7 km (4 mi) northwest of Mauna Loa summit at a depth of 12 km (7 mi). A magnitude-3.8 earthquake occurred at 6:15 p.m. on Wednesday, November 23, and was located 9 km (6 mi) southwest of Nā‘ālehu at a depth of 41 km (25 mi).