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Mahawu

Photo of this volcano
  • Country
  • Volcanic Region
  • Landform | Volc Type
  • Last Known Eruption
  • 1.352°N
  • 124.865°E

  • 1,299 m
    4,262 ft

  • 266110
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number


Most Recent Bulletin Report: August 1994 (BGVN 19:08) Citation IconCite this Report

Mudpots, small geysers, and vigorous, noisy fumaroles

Part of the EVS report follows. "During our observations at 1100 on 9 July intense and noisy gas emissions (like a jet engine) occurred near the low NW part of the inner wall of the crater. These gas emissions generated a gray-white plume. This area of the crater was covered by many yellow sulfur deposits. A strong smell of hydrogen sulfide was also noted. An important solfatara zone surrounded the NW, N, NE, and E sides of the green, ~40,000 m3, acidic crater lake. Two small geysers, the one in the N and the other in the NW, were very active (2-3 m height). Several boiling basins and mud pots were active around the lake. It was not possible to get down into the crater without rock climbing equipment, because the crater walls were very steep." EVS observers also proposed that a low part of the S wall had collapsed.

Information Contacts: H. Gaudru, C. Pittet, M. Auber, C. Bopp, and O. Saudan, EVS, Switzerland.

The Global Volcanism Program has no Weekly Reports available for Mahawu.

Bulletin Reports - Index

Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

04/1987 (SEAN 12:04) Tectonic earthquakes, plume, elevated lake temperature

06/1987 (SEAN 12:06) Lake volume and temperature increase, seismicity rises

07/1987 (SEAN 12:07) White plume present, 1977 activity reviewed

08/1987 (SEAN 12:08) 1977 lake data corrected

11/1991 (BGVN 16:11) Increased thermal activity

08/1994 (BGVN 19:08) Mudpots, small geysers, and vigorous, noisy fumaroles




Information is preliminary and subject to change. All times are local (unless otherwise noted)


April 1987 (SEAN 12:04) Citation IconCite this Report

Tectonic earthquakes, plume, elevated lake temperature

Beginning on 17 April, a white plume was observed ~100 m above Mahawu crater. The plume persisted into early May. Between 1 and 22 April, tectonic earthquakes occurred at a rate of 1/day, with no shallow volcanic earthquakes. During the last week of April, tectonic earthquakes occurred at a rate of ~9/day and shallow volcanic events at ~5/day.

Mahawu contains a crater lake with a volume of ~40,000 m3 of greenish-yellow water. On 21 April the temperature of the lake water was 45°C, compared to a normal 20°C measured in September 1986. A strong odor of H2S was also noted by the VSI observer during his 21 April visit. VSI recommended that a circular area extending ~3.5 km from the crater be temporarily closed to public access. In January 1978, the temperature of the lake water reached 70°C without an eruption [but see 12:7 & 8].

Information Contacts: T. Casadevall, USGS & VSI.


June 1987 (SEAN 12:06) Citation IconCite this Report

Lake volume and temperature increase, seismicity rises

A 100-m white plume was first seen emerging from the summit crater on 17 April (12:04). A similar whitish plume was continuously present above the summit in May and June. Both tectonic and volcanic earthquakes had increased at the end of April and continued to be recorded in May and June. By 30 June, the crater lake volume had increased to 45,000 m3 and water temperature had increased to 48°C.

Information Contacts: VSI.


July 1987 (SEAN 12:07) Citation IconCite this Report

White plume present, 1977 activity reviewed

White fume was continuously present above the crater rim to 100 m heights. Fewer than five volcanic earthquakes were recorded/day. Some tectonic earthquakes were also recorded.

In 12:4 we reported that the temperature of the crater lake rose to 70°C in January 1978 without an eruption. However, Nairn and Bachri (1978) report that on 16 November 1977, the crater lake, 800 m in diameter and 10 m deep, was gray colored and turbid with strong central upwelling and had a temperature of 85.5°C [but see 12:8]. Moderately loud explosions were heard every 5-10 minutes followed by 2-3-m-high spearhead projections of water and lake-floor debris. Along the NE shore fine gray mud was deposited to 20 m above the lake. A strong H2S odor was present.

Reference. Nairn, I. and Bachri, S., 1978, Several annotations about Mahawu's crater activities in recent times: Berita Direktorat Geologi, v. 10, no. 5, p. 55.

Information Contacts: VSI.


August 1987 (SEAN 12:08) Citation IconCite this Report

1977 lake data corrected

During the November 1977 visit by Nairn and Bachri, the crater lake was 80 m in diameter and its temperature was 65.5°C (correcting the values reported in 12:07). Lake depth was estimated at 10 m by a guide, based on his earlier observation of the crater floor at a time when the lake was dry. The explosions from the lake were quite small.

Information Contacts: I. Nairn, NZGS Rotorua, New Zealand.


November 1991 (BGVN 16:11) Citation IconCite this Report

Increased thermal activity

Mahawu began to show signs of renewed activity in mid-Nov, about a month after the eruption of Lokon-Empung, 7 km WNW. Temperatures increased at the solfataras and fumaroles in and around the crater lake, and a vapor column rose 50-200 m above the crater. Although no magmatic eruption was observed, mud boiling from the base of the crater lake generated tremor with 1-2 mm amplitude. No volcanic tremor was detected. As of mid-Dec, degassing episodes were decreasing in number and intensity.

Information Contacts: VSI.


August 1994 (BGVN 19:08) Citation IconCite this Report

Mudpots, small geysers, and vigorous, noisy fumaroles

Part of the EVS report follows. "During our observations at 1100 on 9 July intense and noisy gas emissions (like a jet engine) occurred near the low NW part of the inner wall of the crater. These gas emissions generated a gray-white plume. This area of the crater was covered by many yellow sulfur deposits. A strong smell of hydrogen sulfide was also noted. An important solfatara zone surrounded the NW, N, NE, and E sides of the green, ~40,000 m3, acidic crater lake. Two small geysers, the one in the N and the other in the NW, were very active (2-3 m height). Several boiling basins and mud pots were active around the lake. It was not possible to get down into the crater without rock climbing equipment, because the crater walls were very steep." EVS observers also proposed that a low part of the S wall had collapsed.

Information Contacts: H. Gaudru, C. Pittet, M. Auber, C. Bopp, and O. Saudan, EVS, Switzerland.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 7 confirmed Holocene eruptive periods.

1977 Nov 16 Confirmed Eruption VEI: 0

Episode 1 | Eruption
1977 Nov 16 - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity weak or small
1977 Nov 16    - - - - VEI (Explosivity Index)

1958 Jul 12 - 1958 Jul 29 Confirmed Eruption VEI: 2 (?)

Episode 1 | Eruption
1958 Jul 12 - 1958 Jul 29 Evidence from Observations: Reported

List of 9 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash
   - - - -    - - - - Flames
   - - - -    - - - - Lightning
   - - - -    - - - - Lahar or Mudflow
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1958 Jul 12    - - - - Fatalities
1958 Jul 12    - - - - VEI (Explosivity Index)

1952 Jul 2 ± 182 days Confirmed Eruption VEI: 2 (?)

Episode 1 | Eruption
1952 Jul 2 ± 182 days - Unknown Evidence from Observations: Reported

List of 1 Events for Episode 1

Start Date End Date Event Type Event Remarks
1952    - - - - VEI (Explosivity Index)

1904 Oct 4 (in or before) Confirmed Eruption VEI: 2

Episode 1 | Eruption
1904 Oct 4 (in or before) - Unknown Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lahar or Mudflow
1904 Oct 4
(in or before)
   - - - - VEI (Explosivity Index)

1846 Confirmed Eruption VEI: 2

Episode 1 | Eruption
1846 - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
1846    - - - - VEI (Explosivity Index)

1789 Dec 31 ± 365 days Confirmed Eruption VEI: 2

Episode 1 | Eruption
1789 Dec 31 ± 365 days - Unknown Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Property Damage Uncertain
1789 Dec 31 ± 365 days    - - - - VEI (Explosivity Index)

1788 (in or before) Confirmed Eruption  

Episode 1 | Eruption
1788 (in or before) - Unknown Evidence from Observations: Reported

List of 1 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
Deformation History

There is no Deformation History data available for Mahawu.

Emission History

There is no Emissions History data available for Mahawu.

GVP Map Holdings

Maps are not currently available due to technical issues.

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included.

Smithsonian Sample Collections Database

There are no samples for Mahawu in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites