Report on Lokon-Empung (Indonesia) — July 2002
Bulletin of the Global Volcanism Network, vol. 27, no. 7 (July 2002)
Managing Editor: Richard Wunderman.
Lokon-Empung (Indonesia) Increased activity; gas plumes with occassional ash emitted during June and July 2002
Please cite this report as:
Global Volcanism Program, 2002. Report on Lokon-Empung (Indonesia) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 27:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200207-266100
Lokon-Empung
Indonesia
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
During 27 May-4 August 2002, activity was higher than normal at Lokon. Volcanic and tectonic earthquakes dominated the seismicity (table 3). Generally thin white plumes, reported as "ash plumes" after 1 July, were reaching 25-150 m above the crater rim. Tremor amplitude was 0.5-1 mm during 27 May-2 June. The Alert Level was decreased from 3 to 2 during early June and remained at 2 throughout the report period.
Table 3. Earthquakes occurring at Lokon during 3 June-4 August 2002. Courtesy VSI.
| Date | Deep volcanic (A-type) | Shallow volcanic (B-type) | Tectonic |
| 03 Jun-09 Jun 2002 | 18 | 35 | 32 |
| 10 Jun-16 Jun 2002 | 19 | 30 | 29 |
| 17 Jun-23 Jun 2002 | 5 | 30 | 37 |
| 24 Jun-30 Jun 2002 | 14 | 35 | 23 |
| 01 Jul-07 Jul 2002 | 24 | 93 | 30 |
| 08 Jul-14 Jul 2002 | 49 | 111 | 31 |
| 15 Jul-21 Jul 2002 | 7 | 24 | 26 |
| 22 Jul-28 Jul 2002 | 19 | 22 | 41 |
| 29 Jul-04 Aug 2002 | 8 | 38 | 27 |
Geological Summary. The Lokong-Empung volcanic complex, rising above the plain of Tondano in North Sulawesi, includes four peaks and an active crater. Lokon, the highest peak, has a flat craterless top. The morphologically younger Empung cone 2 km NE has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century. A ridge extending 3 km WNW from Lokon includes the Tatawiran and Tetempangan peaks. All eruptions since 1829 have originated from Tompaluan, a 150 x 250 m crater in the saddle between Lokon and Empung. These eruptions have primarily produced small-to-moderate ash plumes that sometimes damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred.
Information Contacts: Dali Ahmad, Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).
