Suoh

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 5.25°S
  • 104.27°E

  • 1000 m
    3280 ft

  • 261270
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Suoh.

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

Index of Monthly Reports

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.

02/1994 (BGVN 19:02) A major earthquake apparently triggers a phreatic eruption 2 weeks later

05/1994 (BGVN 19:05) Water chemistry of the boiling, post-eruption hot-springs


Contents of Monthly Reports

All information contained in these reports is preliminary and subject to change.

All times are local (= UTC + 7 hours)

02/1994 (BGVN 19:02) A major earthquake apparently triggers a phreatic eruption 2 weeks later

. . . an eruption occurred in the Suoh hot-spring field two weeks after a major earthquake in the region [but see 19:4]. If confirmed, it will be the second time in this century that Suoh erupted two weeks after a large earthquake. As of late February, Indonesian scientists had found two new 5-m-diameter craters that were erupting hot gas-charged mud to 10 m height. The public was not allowed within 100 m of the craters.

The earthquake took place on 15 February, a few tens of kilometers SE of Suoh (5.4°S, 104.8°E) and had a shallow focal depth. The earthquake's magnitude was reported as 7.2 by the NEIC, but press reports stated that officials in Jakarta determined it to be M 6.5. The earthquake apparently caused extensive damage and at least 215 deaths . . . .

This latest seismically triggered outburst was less vigorous than the one in 1933 . . . .

Information Contacts: G. Melosh, Unocal Geothermal Division; NEIC; AP.

05/1994 (BGVN 19:05) Water chemistry of the boiling, post-eruption hot-springs

A . . . small eruption at Suoh hot-spring field that expelled gas-charged hot mud [followed] a major, destructive earthquake in the same region (19:02). The earthquake, Ms 7.2, took place at 1707 GMT on 15 February, or in terms of local time and date, at 0007 on 16 February.

"We sent our team to investigate the area where the phreatic explosion occurred. The team arrived at Suoh on 19 February, three days after the earthquake. Two new mud explosion pits, 5 m in diameter, were found W of the Suoh depression. Liquifaction was consistently found at fractures associated with the earthquake. The two explosion pits contained boiling water."

Tables 1 and 2 present data on water and gas samples taken from two sites in the Suoh area during the investigation.

Table 1. Water chemical analyses for two sites in the Suoh hot-spring field (sampled 19 February 1994). Courtesy of VSI.

			Hot Spring   Crater Lake

    Temperature (°C)      97.6          33.0
    pH                    8.12          3.09
    Conductivity (µmhos)  883           967

    Elem (ppm)
    Na+			  299           199
    K+                     20.8          28.4
    Li+                     2.21          2.67
    Ca+2                   12.1           8.33
    Mg+2                    4.7           6.07
    Fe+3                    0.00          1.27
    Mn+2                    0.00          0.00
    As+3                  192             0.005
    SiO2                   18.4         207
    Boron                 604             7.2
    Cl-                   175           308
    SO4                   713            86.5
    HCO2-3                  0.50          --
    F-                      0.40          0.25
    NH3                     --            0.01

Table 2. Gas chemical analyses for two sites in the Suoh hot-spring field (sampled 19 February 1994). Courtesy of VSI.

    Element   Suoh (TB-1), Kawah Api   New explosion pit
                  Porwarnas               (Kawah Baru)
             Total Gas  Dry Gas       Total Gas  Dry Gas
             (mole %)   (mole %)      (mole %)   (mole %)

    H2         0.003      0.89          0.005       0.25
    O2+Ar      0.040     11.9           0.070       3.44
    N2         0.180     53.4           0.120      59.4
    CO         0.002      0.59          0           0
    CO2        0.100     29.7           0.480      23.6
    SO2        0.001      0.30          0.250      12.3
    H2S        0.004      1.19          0.020       0.98
    HCl        0.007      2.08          0.002       0.098
    H2O       99.66        --          97.96         --

Information Contacts: R. Sukhyar, VSI.

The 8 x 16 km Suoh (or Suwoh) depression appears to have a dominantly tectonic origin, but contains a smaller complex of overlapping calderas oriented NNE-SSW. Historically active maars and silicic domes lie along the margins of the depression, which lies along the Great Sumatran Fault that extends the length of the island. Numerous hot springs occur along faults within the depression, which contains the Pematang Bata fumarole field. Large phreatic explosions (0.2 cu km tephra) occurred at the time of a major tectonic earthquake in 1933. Very minor hydrothermal explosions produced two 5-m-wide craters at the time of a February 1994 earthquake.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1933 Jul 10 1933 Aug 5 Confirmed 4 Historical Observations Pematang Bata

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.



Synonyms
Soeoh-Senke | Suwoh


Craters
Feature Name Feature Type Elevation Latitude Longitude
Pematang Bata Crater 1000 m 5° 15' 0" S 104° 16' 0" E
Steam clouds rise above the Danau Asam fumaroles on the west side of lake Asam within the 8 x 16 km Suoh depression in SE Sumatra. Numerous hot springs occur along faults within the depression, which contains the Pematang Bata fumarole field. Prior to the largest explosive eruption in Sumatra during historical time, which took place in 1933, the floor of the Suoh depression was a broad marsh 13 km long in a NNW-SSE direction. The depression appears to be primarily of tectonic origin, but contains historically active maars and silicic domes along its margins.

Anonymous photo, 1990.

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Bellier O, Bellon H, Sebrier M, Sutanto, Maury R C, 1999. K-Ar age of the Ranau Tuffs: implications for the Ranau caldera emplacement and slip-partitioning in Sumatra (Indonesia). Tectonophysics, 312: 347-359.

Neumann van Padang M, 1951. Indonesia. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 1: 1-271.

Newhall C G, Dzurisin D, 1988. Historical unrest at large calderas of the world. U S Geol Surv Bull, 1855: 1108 p, 2 vol.

Smithsonian Institution-GVN, 1990-. [Monthly event reports]. Bull Global Volc Network, v 15-33.

Volcano Types

Caldera(s)
Maar(s)
Lava dome(s)

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Rock Types

Major
No Data (checked)

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
837
2,048
24,619
1,616,500

Affiliated Databases

Large Eruptions of Suoh Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.