Seismicity increased during May 2009 after tectonic earthquakes

Makian remained in repose as tectonic earthquakes striking the region preceded a cluster of volcanic earthquakes during May and early June 2009. Makian lies SW of the S-central portion of Halmahera Island (in the province of Maluku Utara). Some local residents refer to the island as Mt. Kie Besi; however, it is better known under the name of Mt. Makian (other variants include Kie Besi, Makjan, Makyan, and Wakiong).

The last eruption of Makian occurred in 1988 (SEAN 13:07, 13:08, 13:10, and 13:11) and created a volcanic dome or plug on the crater floor with a diameter of 600 m and volume of ~ 282,600 m³. The 1988 eruption led to the temporary evacuation of the island's 15,000 residents (SEAN 13:07). Not previously discussed in the Bulletin, the TOMS image archive shows several SO₂ clouds from the 1988 eruption (during 30 July-5 August 1988) as well as visible and infrared imagery (Sawada, 1994).

The following information was translated from a Center of Volcanology and Geological Hazard Mitigation (CVGHM) report dated 17 July 2009. Authorities raised the hazard status on 2 June 2009 (from normal, Alert Level 1 to 2) due to the following seismic and other observations.

The pattern of earthquakes and tremor, high for most of May 2009, decreased rapidly after the 28th (table 2). Hot explosions continued until at least mid-June from sulfurous vents on the S side of the lava dome. Emissions from these vents were off-white, with weak pressure, and they fed a plume reaching ~ 10 m above the peak.

Table 2. Seismicity recorded at Makian during 1 May-3 June 2009. Courtesy of Center of Volcanology and Geological Hazard Mitigation (CVGHM).

An increase in tectonic earthquakes in the Maluku Utara (N Moluccas) region preceded the increased activity at Makian. No recent morphological changes have been observed. Based on observations up to 30 June 2009, the hazard status was downgraded to Alert Level 1 on 16 July. However, authorities still prohibited people from climbing to the peak.

The MODVOLC system had no recorded thermal alerts from Makian from at least the beginning of 2000 through August 2009.

Reference. Sawada, Y, 1994, Tracking of Regional Volcanic Ash Clouds by Geostationary Meteorological Satellite, in Volcanic Ash and Aviation Safety: Proceedings of the First International Symposium on Volcanic Ash and Aviation Safety, edited by Thomas J. Casadevall, U.S. Geological Survey Bulletin 2047.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://vsi.esdm.go.id/); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/).

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

July 1976 (NSEB 01:10) Cite this Report

Evacuation due to possible pending eruption

The Jakarta Domestic Service reported on 13 June that "the Social Affairs Dept. has designated Malifut County in Kao Subdistrict, North Maluku District, as a resettlement area for 3,250 families being evacuated from Makian Island, because there is a possibility that the volcano on the island will erupt at any time."

Information Contacts: Jakarta DRS, Jakarta.

September 1976 (NSEB 01:12) Cite this Report

Investigation by volcanologists reveal no signs of activity

Fears of renewed activity at Makian, which last erupted in 1890, stemmed from earthquakes felt in the area in 1972. Investigations carried out between January 1973 and July 1976 by GSI volcanologists indicated that the earthquakes recorded were of tectonic origin and that the volcano shows no signs of renewed activity.

Information Contacts: G. de Néve, GSI, Bandung.

July 1988 (SEAN 13:07) Cite this Report

100-year dormancy ends with large ash eruption; 15,000 evacuated; no fatalities

Makian emitted a white fume cloud 500 m above the summit crater on 17 July, ending a 100-year dormancy. Local residents reported a reddish glow at the cloud's base. The 15,000 residents of Makian Island were evacuated to Moti Island, 10 km N, in anticipation of a larger event similar to past violent eruptions. A NOTAM issued on 18 July at 1156 warned aircraft to avoid the area below ~2 km altitude. By 28 July, activity was limited to emission of a white fume cloud. On 29 July at 1115, a 7-km ash column was erupted, and at 1121, a larger explosion ejected an 8-km cloud. VSI monitored the eruption from its observation post on Moti Island. Smaller explosions occurred that afternoon and were continuing as of 1 August.

GMS satellite imagery first showed an eruption plume on 29 July [at] 1200, when a cloud 55 km wide and 100 km long extended SW from Makian (figure 1). Its coldest area was from -68 to -75°C, corresponding to an altitude of 14-16 km asl (figure 2). Plumes were not evident at 1800 or 2100. Small volcanic-like clouds, ~30 km wide and 130 km long, were seen from Makian to the WSW at 2100 on 30 July and 0300, 0900, 1200 on 31 July. Other small clouds seen 1-4 August may be atmospheric.

Figure 1. Portions of four infrared GMS satellite images on 29 and 31 July 1988, showing clouds that may have been erupted from Makian. Arrows indicate the clouds, apparently attached to the volcano at 1200 on 29 July and at 1200 on 31 July. Courtesy of Y. Sawada.

Figure 2. Temperature gradients in Makian's 29 July 1988 eruption cloud, measured from three GMS infrared images. The volcano is indicated by a solid triangle. Courtesy of Y. Sawada.

Information Contacts: VSI; J. Latter, DSIR Geophysics, New Zealand; Y. Sawada, JMA.

August 1988 (SEAN 13:08) Cite this Report

Weak steam emission and seismicity

Smaller explosions continued until early August, then activity steadily decreased. Weak emissions of white steam reached more than 100 m above the crater rim during August. About 17 volcanic and seven tectonic earthquakes were registered daily.

Information Contacts: VSI.

October 1988 (SEAN 13:10) Cite this Report

Satellite data on July plumes

New data from Japan's GMS satellite.... An image at 1200 on 29 July (figure 1) shows a dense plume with a surface temperature of -70°C (figure 2), suggesting an altitude of 15.2 km (table 1).

Table 1. Analysis of GMS satellite data by Yosihiro Sawada, with parameters of the 29 July Makian plume and possible eruption clouds on 31 July 1988.

By the time of the next image, three hours later, the plume was detached from the volcano and was noticeably more diffuse. Possible volcanic plumes were also detected on GMS imagery returned 31 July (figures 1 and 3), but no ground reports of large eruption clouds are known at those times.

Figure 3. Temperature gradients in the clouds shown in figure 1. Makian is marked by a solid triangle. Courtesy of Y. Sawada.

Information Contacts: Y. Sawada, JMA.

November 1988 (SEAN 13:11) Cite this Report

More details on July-August eruption

. . . . The number of shallow volcanic earthquakes began to increase sharply on 20 July. Based on seismic and visual data, VSI anticipated that an eruption would begin within two weeks, and the 15,000 residents of Makian Island were evacuated to Moti Island, ~6 km to the N.

On 28 July, 521 seismic events were recorded, and tremor began . . . at 2200. The eruption started the next morning at 1112 with a continuous thunderous explosion that was clearly heard on Moti Island. A dark ash cloud reached 8-10 km height. On 30 July at 1006, an explosion was followed by nuées ardentes that advanced E (along the Ng. Powate valley) and N (Ng. Para valley). Originating from ~1,200 m asl, the nuées ardentes descended to 250 m altitude, and some finally reached the sea. A series of smaller explosions began on 31 July and continued until 6 August, feeding ash columns that decreased from 6 to 1-2 km above the crater.

As of the first week in December, white fume was still rising weakly from the crater. Seismicity continued to decrease, with 17 tectonic and 14 volcanic earthquakes recorded 1-7 December.

Information Contacts: VSI.

September 2001 (BGVN 26:09) Cite this Report

Brush fire leads to a falsely alleged 16-17 August 2001 eruption report

Makian was falsely alleged to have begun erupting at 1930 on 16 August 2001. The same Jakarta news article also reported that the volcano continued to spew lava on 17 August forcing residents to evacuate. The article also noted that hot ash and debris were ejected to a height of 20 m and dark clouds rose 75 m.

The Volcanological Survey of Indonesia (VSI) later indicated that the report was false. An observer had mistakenly interpreted the glow from a brush fire as volcanic activity. VSI has not reported any recent volcanic activity at Makian.

Information Contacts: Dali Ahmad, Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).; Darwin VAAC, Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, Northern Territory 0811, Australia; Meteorological and Geophysical Agency of Indonesia (Badan Meteorologi dan Geofisika, BMG), Jalan Angkasa I/2 Kemayoran, Jakarta Pusat 10720, Indonesia (URL: http://www.bmg.go.id/), Société Volcanologique Européenne.

July 2009 (BGVN 34:07) Cite this Report

Seismicity increased during May 2009 after tectonic earthquakes

Makian remained in repose as tectonic earthquakes striking the region preceded a cluster of volcanic earthquakes during May and early June 2009. Makian lies SW of the S-central portion of Halmahera Island (in the province of Maluku Utara). Some local residents refer to the island as Mt. Kie Besi; however, it is better known under the name of Mt. Makian (other variants include Kie Besi, Makjan, Makyan, and Wakiong).

The last eruption of Makian occurred in 1988 (SEAN 13:07, 13:08, 13:10, and 13:11) and created a volcanic dome or plug on the crater floor with a diameter of 600 m and volume of ~ 282,600 m³. The 1988 eruption led to the temporary evacuation of the island's 15,000 residents (SEAN 13:07). Not previously discussed in the Bulletin, the TOMS image archive shows several SO₂ clouds from the 1988 eruption (during 30 July-5 August 1988) as well as visible and infrared imagery (Sawada, 1994).

The following information was translated from a Center of Volcanology and Geological Hazard Mitigation (CVGHM) report dated 17 July 2009. Authorities raised the hazard status on 2 June 2009 (from normal, Alert Level 1 to 2) due to the following seismic and other observations.

The pattern of earthquakes and tremor, high for most of May 2009, decreased rapidly after the 28th (table 2). Hot explosions continued until at least mid-June from sulfurous vents on the S side of the lava dome. Emissions from these vents were off-white, with weak pressure, and they fed a plume reaching ~ 10 m above the peak.

Table 2. Seismicity recorded at Makian during 1 May-3 June 2009. Courtesy of Center of Volcanology and Geological Hazard Mitigation (CVGHM).

An increase in tectonic earthquakes in the Maluku Utara (N Moluccas) region preceded the increased activity at Makian. No recent morphological changes have been observed. Based on observations up to 30 June 2009, the hazard status was downgraded to Alert Level 1 on 16 July. However, authorities still prohibited people from climbing to the peak.

The MODVOLC system had no recorded thermal alerts from Makian from at least the beginning of 2000 through August 2009.

Reference. Sawada, Y, 1994, Tracking of Regional Volcanic Ash Clouds by Geostationary Meteorological Satellite, in Volcanic Ash and Aviation Safety: Proceedings of the First International Symposium on Volcanic Ash and Aviation Safety, edited by Thomas J. Casadevall, U.S. Geological Survey Bulletin 2047.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://vsi.esdm.go.id/); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/).