Crater water boils; diffuse, white plume increases to 50 m

This volcano is well known for three summit crater lakes, each a different color. We last reported minor bubbling in a crater lake Tiwu Nua Muri Kooh Tai lake in 1995 (BGVN 20:06). Between 15 and 19 May 1995, rescuers searched for the body of a Dutch tourist who had fallen into the crater lake but they did not find it.

2013 activity.The Center of Volcanology and Geological Hazard Mitigation (CVGHM) reported that on 6, 10, and 12 June 2013, and during 14 June-9 July 2013, the color of the water in Kelimutu's Crater II (Tiwu Nua Muri Kooh Tai Crater) was bluish white. Diffuse white plumes rose as high as 50 m above the lake's surface and in some areas the water appeared or sounded like it was boiling. A sulfur odor was also reported. The water in Crater I (Tiwu Ata Polo) was light green and churned, and the water in Crater III (Tiwu Ata Mbupu) was mossy green.

On 3 June 2013, a change was observed in the color of the lake water in Crater II, going from blue to a café latte (light tan), accompanied by white smoke under weak to medium pressure, rising 50 meters above the surface of the lake. From the southern side of Crater II a bubbling sound of boiling was heard near the wall separating Crater I from Crater II. The smell of sulphur gas was quite sharp in the vicinity of the crater and at nighttime a weak to medium smell of this gas could be discerned in Pemo Village which is 3 kms from the peak of Kelimutu. On 4 June 2013 at 1400 hours local time the status of Kelimutu was upgraded from Alert Level 1 (Normal) to Alert Level 2 (Waspada).

On 6 June 2013 water in Crater II was a bluish white (like a salty egg), with sparse to medium white smoke under weak to strong pressure extending up 10-35 meters above the lake surface. A weak to strong bubbling sound of boiling water was heard on the southern side of the crater. A medium to sharp smell of sulphurous gas was evident as was the withering vegetation.

On 10 June 2013 water in Crater II was still a bluish white with medium to dense white smoke extending up 40-50 m above the lake surface. A bubbling sound of boiling water could be heard on the southern side of the crater. A medium smell of sulphurous gases was discernible.

On 12 June 2013, smoke rising from the surface of the lake extended to only about 10-30 meters above the lip of the crater. There was a rather acrid smell of sulphurous fumes. Eruptive and hot air noises were audible two times and the water in the crater lake still appeared to be boiling.

From 14 June to 9 July 2013, water in Crater II visually still appeared bluish white with sparse white smoke rising from the surface of the lake about 2-10 meters into the atmosphere (dominant height was not observed). There was a weak to medium (with weak dominating) smell of sulphurous gases. At one point bubbling water was noticeable but it was clearly under weak pressure. Water from Crater III was calm and moss-green in color.

During 22-29 June 2013 sulfur dioxide concentrations in Crater II were occasionally 2.8 ppm, when the wind blew the gas towards the sensor. CVGHM noted that plumes rising from the lakes became lower and barely visible during 3 June-9 July, and that the hissing or "rustling sound" of water from near the dividing wall of craters I and II had gradually faded away. Based on visual observations, seismicity, and gas emissions, CVGHM lowered the Alert Level to 1 (on a scale of 1-4) on 12 July (figure 4).

During 13 - 18 June 2013, local tectonic quakes peaked at 139 before undergoing a decrease as of 17 June 2013. Shallow (VB) and deep (VA) volcanic earthquakes occurred intensely each day, reaching a a peak of 13 shallow volcanic quakes 19-24 June 2013 and then tended to decline (figure 5). Deep volcanic quakes peaked at 14 during 1-6 July 2013 and then subsided.

No thermal alerts were recorded by MODVOLC for the past twelve months beginning in mid-July 2012.

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

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

April 1986 (SEAN 11:04) Cite this Report

Gas emission from crater lake; felt earthquake

". . . signs of unrest from the Tiwu Nua Muri crater . . . consisted of increased gas bubbling from the crater lake beginning on 27 April and a felt earthquake on 28 April."

Information Contacts: Olas, Suratman, Suparto, Kaswanda, and A. Sudradjat, VSI.

November 1989 (SEAN 14:11) Cite this Report

Degassing from one of three crater lakes and flank fumaroles

In November, moderate degassing with a weak sulfur odor occurred from the the E crater's Tiwu Ata Polo, reddish in 1986 and dark green in 1989. No degassing was evident from the light green Tiwu Nua Muri Kooh Tai in the central crater. A small amount of sulfur was deposited around the lakeshore. In the W crater, Tiwu Ata Mbupu, dark brown in May, was greenish in November. No degassing or other activity was evident. Fumaroles on the upper flanks had temperatures of [96-97°C] in 21°C air. An earthquake was felt at MM II on 28 June at 2255. November seismicity included [three] A-type and [two] B-type events, plus [23] local and [37] distant tectonic earthquakes.

Information Contacts: VSI.

June 1993 (BGVN 20:06) Cite this Report

Increased seismicity for three months

[Seismicity rose during February-April 1993, with 318 deep and 196 shallow earthquakes, but declined in June (VSI, 1993a).] (originally in 20:06)

Reference. Volcanological Survey of Indonesia, 1993a, Kelimutu Volcano: Journal of Volcanic Activity in Indonesia, v. 1:1/2, p. 14.

Information Contacts: VSI.

June 1995 (BGVN 20:06) Cite this Report

Minor bubbling in very acidic crater lake

Between 15 and 19 May 1995 a search was conducted for the body of a missing Dutch tourist who had fallen into one of Kelimutu's three crater lakes (figures 1, 2, and 3). During the search of the turquoise-blue Tiwu Nua Muri Kooh Tai lake, ~600 x 380 m in size and located 100-150 m below the crater rim, pH measured by litmus-paper was 0.5. Access to the crater lake was achieved by rope-aided descent, but rocks on the crater wall were very loose and rockfalls were frequent. A portable boat was used to tow a dredging net to comb the 3-6 m depth range of the entire lake. The water temperature was 37°C, ~8° cooler than the air. A film of yellow sulfur (~30 x 150 m) floated on the lake's surface. The searchers breathed bottled oxygen because of the high levels of SO₂ in the air, which measured 5 ppm. On 18 May "little bubbles or very small fountains" were observed within the lake. Although the body was not recovered, the search was terminated on 19 May.

Further Reference. Outdoor Magazine, Bergingsactie op een actieve vulkaan, De Kelimutu Zwijgt, 3e jaargang:4, July 1995, p. 40-45 (in Dutch, with 14 photos).

Information Contacts: Ton Biesemaat, Outdoor Magazine, Netherlands; VSI; AP; UPI.

June 2013 (BGVN 38:06) Cite this Report

Crater water boils; diffuse, white plume increases to 50 m

This volcano is well known for three summit crater lakes, each a different color. We last reported minor bubbling in a crater lake Tiwu Nua Muri Kooh Tai lake in 1995 (BGVN 20:06). Between 15 and 19 May 1995, rescuers searched for the body of a Dutch tourist who had fallen into the crater lake but they did not find it.

2013 activity.The Center of Volcanology and Geological Hazard Mitigation (CVGHM) reported that on 6, 10, and 12 June 2013, and during 14 June-9 July 2013, the color of the water in Kelimutu's Crater II (Tiwu Nua Muri Kooh Tai Crater) was bluish white. Diffuse white plumes rose as high as 50 m above the lake's surface and in some areas the water appeared or sounded like it was boiling. A sulfur odor was also reported. The water in Crater I (Tiwu Ata Polo) was light green and churned, and the water in Crater III (Tiwu Ata Mbupu) was mossy green.

On 3 June 2013, a change was observed in the color of the lake water in Crater II, going from blue to a café latte (light tan), accompanied by white smoke under weak to medium pressure, rising 50 meters above the surface of the lake. From the southern side of Crater II a bubbling sound of boiling was heard near the wall separating Crater I from Crater II. The smell of sulphur gas was quite sharp in the vicinity of the crater and at nighttime a weak to medium smell of this gas could be discerned in Pemo Village which is 3 kms from the peak of Kelimutu. On 4 June 2013 at 1400 hours local time the status of Kelimutu was upgraded from Alert Level 1 (Normal) to Alert Level 2 (Waspada).

On 6 June 2013 water in Crater II was a bluish white (like a salty egg), with sparse to medium white smoke under weak to strong pressure extending up 10-35 meters above the lake surface. A weak to strong bubbling sound of boiling water was heard on the southern side of the crater. A medium to sharp smell of sulphurous gas was evident as was the withering vegetation.

On 10 June 2013 water in Crater II was still a bluish white with medium to dense white smoke extending up 40-50 m above the lake surface. A bubbling sound of boiling water could be heard on the southern side of the crater. A medium smell of sulphurous gases was discernible.

On 12 June 2013, smoke rising from the surface of the lake extended to only about 10-30 meters above the lip of the crater. There was a rather acrid smell of sulphurous fumes. Eruptive and hot air noises were audible two times and the water in the crater lake still appeared to be boiling.

From 14 June to 9 July 2013, water in Crater II visually still appeared bluish white with sparse white smoke rising from the surface of the lake about 2-10 meters into the atmosphere (dominant height was not observed). There was a weak to medium (with weak dominating) smell of sulphurous gases. At one point bubbling water was noticeable but it was clearly under weak pressure. Water from Crater III was calm and moss-green in color.

During 22-29 June 2013 sulfur dioxide concentrations in Crater II were occasionally 2.8 ppm, when the wind blew the gas towards the sensor. CVGHM noted that plumes rising from the lakes became lower and barely visible during 3 June-9 July, and that the hissing or "rustling sound" of water from near the dividing wall of craters I and II had gradually faded away. Based on visual observations, seismicity, and gas emissions, CVGHM lowered the Alert Level to 1 (on a scale of 1-4) on 12 July (figure 4).

During 13 - 18 June 2013, local tectonic quakes peaked at 139 before undergoing a decrease as of 17 June 2013. Shallow (VB) and deep (VA) volcanic earthquakes occurred intensely each day, reaching a a peak of 13 shallow volcanic quakes 19-24 June 2013 and then tended to decline (figure 5). Deep volcanic quakes peaked at 14 during 1-6 July 2013 and then subsided.

No thermal alerts were recorded by MODVOLC for the past twelve months beginning in mid-July 2012.

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