Saturday, 14 September 2013

Mount Rinjani : represents an important nature reserve and water catchement area

Mount Rinjani

Mount Rinjani
A massive eruption of Rinjani in 1258 CE may have triggered the Little Ice Age.
Lombok is one of the Lesser Sunda Islands, a small archipelago which, from west to east, consists of Bali, Lombok, Sumbawa, Flores, Sumba and the Timor islands; all are located at the edge of the Australian continental shelf. Volcanoes in the area are formed due to the action of oceanic crusts and the movement of the shelf itself. Rinjani is one of at least 129 active volcanoes in Indonesia, four of which belong to the volcanoes of the Sunda Arc trench system forming part of the Pacific Ring of Fire â€" a section of fault lines stretching from the Western Hemisphere through Japan and South East Asia. The islands of Lombok and Sumbawa lie in the central portion of the Sunda Arc. The Sunda Arc is home to some of the world's most dangerous and explosive volcanoes. The eruption of nearby Mount Tambora on Sumbawa is known for the most violent eruption in recorded history on 15 April 1815, with a scale 7 on the VEI.

Mount Rinjani
Mount RinjaniThe highlands are forest clad and mostly undeveloped. The lowlands are highly cultivated. Rice, soybeans, coffee, tobacco, cotton, cinnamon, cacao, cloves, cassava, corn, coconuts, copra, bananas and vanilla are the major crops grown in the fertile soils of the island. The slopes are populated by the indigenous Sasak population. There are also some basic tourist related activities established on Rinjani primarily in or about the village of Senaru.
The geology and tectonic setting of Lombok are described as being in the central portion of the Sunda Arc. The oldest exposed rocks are Miocene, suggesting that subduction and volcanism began considerably later than in Java and Sumatra to the west, where there are abundant volcanic and intrusive rocks of Late Mesozoic age. The islands are located on the eastern edge of the Sunda shelf, in a zone where crustal thickness is apparently rapidly diminishing, from west to east.
The Rinjani caldera forming eruption is thought to have occurred in the 13th century. Dated to "late spring or summer of 1257," this eruption is now considered the likely source of high concentrations of sulfur found in widely dispersed ice core samples and may have been "the most powerful volcanic blast since humans learned to write."
Eruption rate, eruption sites, eruption type and magma composition have changed during the last 10,000 years before the caldera forming eruption. The eruptions of 1994 and 1995 have presented at Gunung Baru in the center of this caldera and lava flows from subsequent eruptions have entered the lake. This cone has since been renamed Gunung Barujari (or 'Gunung Baru Jari' in Indonesian).
The 1st historical eruption occurred in September 1847. The most recent eruption of Mount Rinjani was in May 2010 and the most recent significant eruptions occurred during a spate of activity from 1994 to 1995 which resulted in the further development of Gunung Barujari. Historical eruptions at Rinjani dating back to 1847 have been restricted to Barujari cone and the Rombongan dome and consist of moderate explosive activity and occasional lava flows that have entered Segara Anak lake. The eruptive history of Rinjani prior to 1847 isn't available as the island of Lombok is in a location that remained very remote to the record keeping of the era.
On 3 November 1994, a cold lahar from the summit area of Rinjani volcano traveled down the Kokok Jenggak River killing thirty people from the village of Aikmel who were caught by surprise when collecting water from the river in the path of the flow.
On 3 November 1994, a cold lahar from the summit area of Rinjani volcano traveled down the Kokok Jenggak River killing thirty people from the village of Aikmel who were caught by surprise when collecting water from the river in the path of the flow. One person remained missing as of 9 November 1994. No damage to the village was reported. Local volcanologists noted that additional lahars could be triggered by heavy rainfall.
During 4 June 1994-January 1995 the DVGHM noted that explosions occurred on Rinjani. Those explosions came from the Barujari volcano. At 0530 on 1 October 2004 Rinjani erupted. The eruption caused authorities to immediately raise the hazard status to Alert Level 3 (Orange). Details regarding the initial 1 October 2004 eruption are indistinct. During 2â€"5 October 2004 explosions sent ash columns ~300 to 800 metres above the summit. Gray, thick ash columns drifted to the north and detonation sounds accompanied every explosion. Successive explosions occurred at intervals of 5 to 160 minutes. Explosions vented on the north eastern slope of Barujari volcano. Some material also vented from Barujari's peak and fell down around its edifice. A press report in the Jakarta Post indicated that evacuations were not considered necessary. A Volcanic Explosivity Index (VEI):2 rating was issued for the activity between 1 May 2004 through to (on or after) 5 October 2004.
Between 3 June 1994 and 21 November 1994 records of Rinjani's eruptive history indicate activity accorded Volcanic Explosivity Index with a rating of 3(?) with the area of activity described as Gunung Barujari. Eruptive characteristics documented for the events of that time are described as, central vent eruption with an explosive eruption, with pyroclastic flow(s), lava flow(s), fatalities and mudflow(s) (lahars).
Between 28 March 1966 and 8 August 1966 records of Rinjani's eruptive history indicate activity accorded a Volcanic Explosivity Index rating of 1. Lava volume of 6.6 x 106 m3 and a tephra volume of 2 x 104 m3 was recorded. The area of activity described was the east side of Barujari (2250 m). Eruptive characteristics were documented as a central vent eruption, explosive eruption and lava flow(s).
In December 1944 Rinjani appears to have had a significant event. Between December 25, 1944 and 1(?) January 1945 eruptive activity is rated 2 on the Volcanic Explosivity Index (VEI) The event has been listed in the historical records of the Global Volcanism Program indicating a lava volume: of 7.4 x 107 m3 occurring in an area of activity on the north west flank of Barujari (Rombongan). The eruptive characteristics are described a central vent eruption on the flank (excentric) vent, a crater lake eruption, explosive eruption, lava flow(s) and a lava dome extrusion with associated damage to land, property.
The volcano and the caldera are protected by the Gunung Rinjani National Park established in 1997. Tourism is increasingly popular with trekkers able to visit the rim, make their way into the caldera or even to make the more arduous climb to the highest point; fatalities, however, aren't unheard of. In July 2009 the summit route was closed due to volcanic activity at that time and subsequently reopened when the activity decreased. During early 2010 up to and including May 2010 access to Rinjani was at times again restricted due to volcanic activity.
The park is popular for mountain climbs and trekking and represents an important nature reserve and water catchement area. The park is officially 41,330 hectares within the park boundaries and includes a further 66,000 hectares of protected forest outside. The mountain and its satellites form the Mount Rinjani National Park - officially 41,000 hectares within the park boundaries and a further 66,000 hectares of protected forest outside. In 2008, the Indonesian government proposed to UNESCO that Mount Rinjani be one of the world's official geoparks. If this was approved by UNESCO, Mount Rinjani would become the 1st such geological park in Indonesia.
It has been claimed that the preliminary documentation required for UNESCO registration has not received sufficient support from the Nusa Teggara Barat government offices. Among the requirements to become a geo-park sufficient information must be supplied to show that the location has sufficient and appropriate management, information services, access to educational instruction to facilitate "knowledge-based geotourism", the implementation of a sustainable regional economy, biodiversity conservation, and to have established public access to the park area.
Mount Rinjani has obtained the World Legacy Award from Conservation International and Traveller, and was a finalist for Tourism for Tomorrow Awards (2005 dan 2008) from the World Travel Tourism Council (WTTC).
Rinjani owl is found in 2003 and after 10 years evidence research is recognized as a new endemic owl.


In December 2010, a photo of eruption of Rinjani won 2010 National Geographic Photography Contest. The photo, taken by Singaporean photographer Aaron Lim Boon Teck won the contest, and described by the judge as "best represented the craft of photography. Not only is the light subtle and beautiful, and not only is it a lovely scene, but there's a volcanic eruption going on in the background."

Related Sites for Mount Rinjani