Report on Lokon-Empung (Indonesia) — December 2002
Bulletin of the Global Volcanism Network, vol. 27, no. 12 (December 2002)
Managing Editor: Richard Wunderman.
Lokon-Empung (Indonesia) Higher-than-normal activity continues through at least December 2002
Please cite this report as:
Global Volcanism Program, 2002. Report on Lokon-Empung (Indonesia) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 27:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200212-266100
Lokon-Empung
Indonesia
1.3644°N, 124.7992°E; summit elev. 1580 m
All times are local (unless otherwise noted)
Higher-than-normal activity continued at Lokon-Empung during August-December 2002. Throughout the report period a "white-thin ash plume" rose 25-75 m above the crater rim. No ashfall was reported. Seismicity was dominated by shallow volcanic and tectonic earthquakes (table 4).
Table 4. Earthquakes recorded at Lokon during 5 August-29 December 2002. No reports were issued during 11 November-22 December. Courtesy VSI.
| Date | Deep volcanic (A-type) | Shallow volcanic (B-type) | Tectonic |
| 05 Aug-11 Aug 2002 | 19 | 42 | 32 |
| 12 Aug-18 Aug 2002 | 9 | 11 | 35 |
| 19 Aug-25 Aug 2002 | 14 | 51 | 42 |
| 26 Aug-01 Sep 2002 | 19 | 53 | 28 |
| 02 Sep-08 Sep 2002 | 14 | 39 | 32 |
| 09 Sep-15 Sep 2002 | 18 | 50 | 33 |
| 16 Sep-22 Sep 2002 | 16 | 37 | 39 |
| 23 Sep-29 Sep 2002 | 2 | 18 | 46 |
| 30 Sep-06 Oct 2002 | 9 | 17 | 39 |
| 07 Oct-13 Oct 2002 | 5 | 7 | 35 |
| 14 Oct-20 Oct 2002 | 5 | 4 | 29 |
| 21 Oct-27 Oct 2002 | 6 | 25 | 44 |
| 28 Oct-03 Nov 2002 | 0 | 1 | 35 |
| 04 Nov-10 Nov 2002 | 1 | 4 | 26 |
| 23 Dec-29 Dec 2002 | 29 | 74 | 31 |
During the week of 4-10 November, the hazard status was reduced from Alert Level 2 to 1 (on a scale of 1-4). On 23 December a "white-thick ash plume" rose 100-250 m over Tompaluan crater. No ashfall was reported. [A later report did note ashfall.] The same day, volcanic tremor with an amplitude of 0.5-2 mm occurred. A total of 42 emissions were reported during 23-29 December. The Alert Level returned to 2 by the end of the report period.
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: Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).
