Bulletin of the Global Volcanism Network

All reports of volcanic activity published by the Smithsonian since 1968 are available through a monthly table of contents or by searching for a specific volcano. Until 1975, reports were issued for individual volcanoes as information became available; these have been organized by month for convenience. Later publications were done in a monthly newsletter format. Links go to the profile page for each volcano with the Bulletin tab open.

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 Bulletin of the Global Volcanism Network - Volume 42, Number 02 (February 2017)

Managing Editor: Edward Venzke

Marapi (Indonesia)

Phreatic explosion on 14 November 2015 causes ashfall on the SW flank

Marapi (Indonesia) — February 2017 Citation iconCite this Report



0.381°S, 100.473°E; summit elev. 2891 m

All times are local (unless otherwise noted)

Phreatic explosion on 14 November 2015 causes ashfall on the SW flank

Explosions occurred at Marapi (not to be confused with the better known Merapi on Java) during August 2011; March, May, and September 2012; and February 2014 (BGVN 40:05). This report discusses activity during 2015 and 2016. All information was provided by the Indonesian Center of Volcanology and Geological Hazard Mitigation (PVMBG, also known as CVGHM). During the reporting period, the Alert Level remained at 2 (on a scale of 1-4); residents and visitors were advised not to enter an area within 3 km of the summit.

According to PVMBG, diffuse white plumes rose as high as 300 above Marapi's crater during February-25 May 2015, 150 m above the crater during 1 August-16 November 2015, and 250 m above the crater during 1 November 2015-19 January 2016. Inclement weather often prevented observations.

Seismicity fluctuated during this time, dominated by earthquakes centered a long distance from the volcano. However, tremor increased significantly during August 2015 through at least the middle of January 2016 (figure 4). A phreatic explosion at 2233 on 14 November 2015, generated an ash plume, and ashfall was noted in Panyalaian and Aia Angek on the SW flank.

Figure (see Caption) Figure 4. Types and daily number of earthquakes recorded at Marapi during 1 January 2015-18 January 2016. Key: eruptive earthquakes (Letusan), emission-type "blowing" earthquakes (Hembus), shallow earthquakes (VB), deep earthquakes (VA), local earthquakes (Lokal), and long-distance earthquakes (Jauh). The terms shallow and deep were not quantified. Courtesy of PVMBG (23 January 2016 report).

Geologic Background. 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 2000 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: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).

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 Atmospheric Effects

The enormous aerosol cloud from the March-April 1982 eruption of Mexico's El Chichón persisted for years in the stratosphere, and led to the Atmospheric Effects section becoming a regular feature of the Bulletin. Descriptions of the initial dispersal of major eruption clouds remain with the individual eruption reports, but observations of long-term stratospheric aerosol loading will be found in this section.

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 Additional Reports

Reports are sometimes published that are not related to a Holocene volcano. These might include observations of a Pleistocene volcano, earthquake swarms, or floating pumice. Reports are also sometimes published in which the source of the activity is unknown or the report is determined to be false. All of these types of additional reports are listed below by subregion and subject.


False Report of Sea of Marmara Eruption

Africa (northeastern) and Red Sea

False Report of Somalia Eruption

Africa (eastern)

False Report of Elgon Eruption

Kermadec Islands

Floating Pumice (Kermadec Islands)

1986 Submarine Explosion

Tonga Islands

Floating Pumice (Tonga)

Fiji Islands

Floating Pumice (Fiji)

New Britain


Andaman Islands

False Report of Andaman Islands Eruptions

Sangihe Islands

1968 Northern Celebes Earthquake

Kawio Barat


False Report of Mount Pinokis Eruption

Southeast Asia

Pumice Raft (South China Sea)

Land Subsidence near Ham Rong

Ryukyu Islands and Kyushu

Pumice Rafts (Ryukyu Islands)

Izu, Volcano, and Mariana Islands

Mikura Seamount

Acoustic Signals in 1996 from Unknown Source

Acoustic Signals in 1999-2000 from Unknown Source

Kuril Islands

Possible 1988 Eruption Plume



Aleutian Islands

Possible 1986 Eruption Plume


False Report of New Volcano




La Lorenza Mud Volcano



Pacific Ocean (Chilean Islands)

False Report of Submarine Volcanism

Central Chile and Argentina

Estero de Parraguirre

West Indies

Mid-Cayman Spreading Center

Atlantic Ocean (northern)

Northern Reykjanes Ridge


Azores-Gibraltar Fracture Zone

Antarctica and South Sandwich Islands

Jun Jaegyu

East Scotia Ridge

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Special Announcement Reports