Eruptive activity at Marapi was absent for seven years following a short ash explosion in August 2004 (BGVN 30:01). Intermittent activity began again with eruptions in August and October 2011, followed by ash plumes during February-March 2012 and February 2014. The only additional information after the February 2014 activity was a Center of Volcanology and Geological Hazard Mitigation (CVGHM) report that during February-25 May 2015 diffuse white plumes rose as high as 300 m and seismicity fluctuated. The CVGHM kept the Alert Level at 2 (on a scale of 1-4), a status where residents and visitors are advised not to enter an area within 3 km of the summit.

Activity during 2011. Ash eruptions on 3 August 2011 had been preceded by increased seismicity and white plumes since 21 June (BGVN 36:07). Dense gray plumes rose 300-1,000 m above the crater on eight occasions that day; two more eruptions occurred on 9 August. No further activity was noted until the Darwin Volcanic Ash Advisory Centre (VAAC) reported that a pilot on 11 October saw a plume rising to an altitude of 3.7 km, though ash was not identified in satellite imagery. However, based on information from CVGHM, the VAAC reported that on 12 October 2011 an ash plume rose to an altitude of 3 km and drifted E.

Activity during 2012. According to a BNO News article from 5 March 2012, several eruptions had produced ash plumes during the previous week (approximately 27 February-4 March), with one that rose 1 km above the crater on 4 March and drifted 10 km S. An approximately 10-minute-long eruption produced an ash plume that rose 600 m on 18 May which was described in an MI News article. Media reports (Big Pond News) noted another eruption on 26 September with an ash plume that rose 1.5 km above the crater.

Activity during 2014. According to a news article from 5 February 2014 (Metro TV), four explosions occurred in early February. One was followed by ashfall in the Tarab River area and Batu Sangkar (17 km SE). News media reported an explosion on 26 February that caused ashfall in areas as far as 10 km S.

Geological Summary. Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2,000 m above the Bukittinggi Plain in the Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time.

Information Contacts: Indonesian Center of Volcanology and Geological Hazard Mitigation, Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); Metro TV News (URL: http://www.metrotvnews.com/read/newsvideo/2011/08/10/133771/Gunung-Marapi-Masih-Waspada); BNO News (URL: http://channel6newsonline.com/2012/03/indonesias-mount-marapi-still-highly-active/); MI News 26 (URL: http://www.minews26.com/content/?p=16895); Big Pond News (URL: http://bigpondnews.com/articles/World/2012/09/27/Volcano_erupts_with_smoke_on_Sumatra_799600.html); Metro TV (URL: http://www.metrotvnews.com/); The Free Press Journal (URL: http://freepressjournal.in/volcano-erupts-in-indonesia-2/).