Mount Merapi Overview Region Middle Java (Magelang, Boyolali, Klaten), Daerah Istimewa Yogyakarta (Sleman) Latitude 7.54°S Longitude 110.446°E Summit 2910 m Elevation 9547 ft Primary Volcano Type Stratovolcano Last Known Eruption 2024 CE Literature and Analysis Eruptive History Geomorphology Geological Settings Structure Reference Eruptive History Geomorphology Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo. Geological Settings Tab Content Structure Tab Content Reference Tab Content

Mount Krakatau Overview Region South Lampung, Lampung Latitude 6.1009°S Longitude 105.4233°E Summit 285 m Elevation 935 ft Primary Volcano Type Caldera Last Known Eruption 2023 CE Literature and Analysis Eruptive History Geomorphology Geological Feature Reference Eruptive History Geomorphology Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo. Geological Feature Following [5-6], the stratigrahpy of krakatoa divided into 4 eruption products from old to young as follows: Pre-historic Krakatoa; these products were erupted around 416 AD and consist of 2 dacitic lava flows, 1 pyroclastic flow and 1 pyroclastic fall. Young Krakatoa; these products were erupted around 1200 AD and consist of 3 eruption centers: Rakata, Danan and Parbuwatan. During this period, the products were dominated by lava. 1883; period of the destruction of the Rakata, Danan and Parbuwatan volcanoes, characterized by the 1883 caldera formation, and produced typical eruptive products. This rock unit was distributed on all three islands—Rakata, Panjang and Sertung—and was composed of pumice pyroclastic flows, minor pyroclastic falls and surge deposits. Anak Krakatoa; since its birth in 1927 to 2017, Anak Krakatoa has erupted at least thirty-two times, showing a combination of explosive and effusive activities. Anak Krakatoa, with an elevation of about 300 m above sea level, is a volcano island, lying in the center of the Krakatoa volcanic complex. It is constructed of alternating layers of 18 lava flows and 18 pyroclastic deposits that have been built since 1927. Reference [1] volcano.si.edu [2] Abdurrachman, M., Widiyantoro, S., Priadi, B., & Ismail, T. (2018). Geochemistry and structure of krakatoa volcano in the Sunda Strait, Indonesia. Geosciences, 8(4), 111. [3] Hidayat, A., Marfai, M. A., & Hadmoko, D. S. (2020, May). Eruption on Indonesia’s volcanic islands: A review of potential hazards, fatalities, and management. In IOP Conference Series: Earth and Environmental Science (Vol. 485, No. 1, p. 012061). IOP Publishing. [4] Mastin, L. G., & Witter, J. B. (2000). The hazards of eruptions through lakes and seawater. Journal of Volcanology and Geothermal Research, 97(1-4), 195-214. [5] Stehn, C. E. (1929). Krakatau: The geology and volcanism of the Krakatau group. [6] Abdurrahman, M., et al. (2018). Geochemistry and Structure of Krakatoa Volcano in the Sunda Strait, Indonesia. Geosciences, 8(4), 111; https://doi.org/10.3390/geosciences8040111

Mount Semeru Overview Region Malang, East Java Latitude 8.108°S Longitude 112.922°E Summit 3657 m Elevation 11998 ft Primary Volcano Type Stratovolcano Last Known Eruption 2024 CE Literature and Analysis Eruptive History Geomorphology Regional Stratigraphy Structure Reference Eruptive History 2011 Dec 29 – 2012 Jul 20 Date Event Type Fatalities VEI (Explositivity Index) Level Event Remarks Reference 2011 Dec 29 Seismicity (volcanic) – 2 – Seismicity increased, and dense white and gray plumes rose as high as 600 m above the Jonggring Seloko crater. [1] 2011 Dec 29 Ash Plume – 2 – Dense white and gray plumes rose as high as 600 m above the Jonggring Seloko crater. [1] 2011 Dec 29 Lava flow – 2 – A 300-m-long lava flow was observed. [1] 2012 Jan 1 Avalanche – 2 – Crater incandescence was observed and avalanches carried incandescent material 200-400 m away from the crater. [1] 2012 Jan 6 Explosion – 2 – Dense gray-white plumes rose 600 m and preceded an explosion on 6 January 2012; the explosion was followed by summit incandescence. [1] 2012 Jan 6 Ash Plume – 2 – Dense gray-white plumes rose 600 m and preceded an explosion. [1] 2012 Jan 7 Lava flow – 2 – Repeated observations of incandescent material flowing up to 400 m SE toward the Besuk Kembar drainage were made during the rest of January. [1] 2012 Jan 30 Thermal Anomaly – 2 – A MODVOLC thermal alert was issued. [1] 2012 Feb 1 Ash Plume – 2 – Dense gray-to-white plumes rose 100-500 m above Jongring Seloko crater and drifted W and N. [1] 2012 Feb 1 Pyroclastic flow – 2 – CVGHM reported that multiple pyroclastic flows traveled 500 and 2,500 m into the Besuk Kembar and Besuk Kobokan rivers (on the S flank). [1] 2012 Feb 1 Incandescence – 2 – Incandescence was visible up to 50 m above the crater. [1] 2012 Feb 2 Explosion – 2 – A large explosion was reported. [1] 2012 Feb 2 Pyroclastic flow – 2 – Just after midnight, a pyroclastic flow traveled 300 m from the Jongring Seloko crater, and by mid-morning it had traveled farther, to 2.5 km from the crater. [1] 2012 Feb 2 VEI (Explosivity Index) – 2 – VEI 2 [1] 2012 Feb 5 Thermal Anomaly – 2 – Three MODVOLC thermal alerts were issued. [1] 2012 Feb 8 Thermal Anomaly – 2 – Seven MODVOLC thermal alerts were issued. [1] 2012 Feb 14 Thermal Anomaly – 2 – Sixteen MODVOLC thermal alerts were issued. [1] 2012 Mar 27 Thermal Anomaly – 2 – Four MODVOLC thermal alerts were issued. [1] 2012 Apr 1 Lava dome – 2 – Observations indicated that the lava dome grew in April. [1] 2012 Apr 12 Thermal Anomaly – 2 – Three MODVOLC thermal alerts were issued. [1] 2012 Apr 21 Thermal Anomaly – 2 – Two MODVOLC thermal alerts were issued. [1] 2012 May 9 Thermal Anomaly – 2 – A MODVOLC thermal alert was issued. [1] 2012 Jul 18 Ash Plume – 2 – Tourists with Volcano Discovery observed that the lava dome was active and growing slowly. They noted an area of incandescence visible at the SW part of the dome inside the half-open summit crater, and it was producing regular small to moderate ash explosions. [1] 2012 Jul 18 Lava dome – 2 – Tourists with Volcano Discovery observed that the lava dome was active and growing slowly. They noted an area of incandescence visible at the SW part of the dome inside the half-open summit crater, and it was producing regular small to moderate ash explosions. [1] 2012 Jul 18 Incandescence – 2 – Tourists with Volcano Discovery observed that the lava dome was active and growing slowly. They noted an area of incandescence visible at the SW part of the dome inside the half-open summit crater, and it was producing regular small to moderate ash explosions. [1] 2010 Jan 5 – 2010 Nov 29 Date Event Type Fatalities VEI (Explositivity Index) Level Event Remarks Reference 2010 Jan 5 Incandescence – 2 – Incandescence at the summit was observed. [1] 2010 Jan 21 Thermal Anomaly – 2 – A MODVOLC thermal alert was issued. [1] 2010 Feb 13 Thermal Anomaly – 2 – A MODVOLC thermal alert was issued. [1] 2010 Feb 20 Thermal Anomaly – 2 – Two MODVOLC thermal alerts were issued. [1] 2010 Feb 25 Lava flow – 2 – PVMBG reported a new lava flow which by 28 February had traveled 750 m. [1] 2010 Feb 27 Thermal Anomaly – 2 – A MODVOLC thermal alert was issued. [1] 2010 Apr 25 Thermal Anomaly – 2 – Thirteen MODVOLC thermal alerts were issued. [1] 2010 May 18 Thermal Anomaly – 2 – Four MODVOLC thermal alerts were issued. [1] 2010 May 25 Thermal Anomaly – 2 – Three MODVOLC thermal alerts were issued. [1] 2010 Jun 14 Thermal Anomaly – 2 – Two MODVOLC thermal alerts were issued. [1] 2010 Jun 19 Thermal Anomaly – 2 – Three MODVOLC thermal alerts were issued. [1] 2010 Jun 28 Thermal Anomaly – 2 – Three MODVOLC thermal alerts were issued. [1] 2010 Jul 5 Thermal Anomaly – 2 – Three MODVOLC thermal alerts were issued. [1] 2010 Jul 14 Thermal Anomaly – 2 – A MODVOLC thermal alert was issued. [1] 2010 Jul 19 Thermal Anomaly – 2 – Three MODVOLC thermal alerts were issued. [1] 2010 Jul 28 Thermal Anomaly – 2 – Four MODVOLC thermal alerts were issued. [1] 2010 Aug 1 Seismicity (volcanic) – 2 – CVGHM reported on that from August to October seismic activity at Semeru had increased. [1] 2010 Aug 6 Thermal Anomaly – 2 – Five MODVOLC thermal alerts were issued. [1] 2010 Aug 15 Thermal Anomaly – 2 – Two MODVOLC thermal alerts were issued. [1] 2010 Aug 24 Thermal Anomaly – 2 – A MODVOLC thermal alert was issued. [1] 2010 Aug 31 Thermal Anomaly – 2 – Three MODVOLC thermal

Mount Bromo Overview Region Probolinggo, East Java Latitude 7.942°S Longitude 112.95°E Summit 2329 m Elevation 7641 ft Primary Volcano Type Stratovolcano(es) Last Known Eruption 2023 CE Literature and Analysis Eruptive History Geomorphology Geological Feature Reference Eruptive History Geomorphology Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo. Geological Feature Bromo volcano elevation is about 2392 m above mean sea level (msl) and 133 m above the base of Tengger Caldera with crater size about 600 m x 800 m. The Crater always releases flue-gasses with high concentration of sulphur [4]. Bromo is a Stromboli volcani with some hazard potentials, they are tephra, heavy volcano dust, poisoned gasses and pyroclastic falls [5]. Caldera Tengger complex consist of some sedimentary formation including, Bromo pyroclasctic fall deposits (BOjp), Batok pyroclastic fall deposits (BAjp), Kursi pyrocalstic fall deposits (Wjp), and Widodaren black rock deposits (WJph) [6]. Reference [1] volcano.si.edu [2] vsi.esdm.go.id [3] Van Gerven, M., & Pichler, H. (1995). Some aspects of the volcanology and geochemistry of the Tengger Caldera, Java, Indonesia: eruption of a K-rich tholeiitic series. Journal of Southeast Asian Earth Sciences, 11(2), 125-133. [4] Maryanto, S., et al. (2017). Temporal Changes of Complete Bougeur Anomalies at Bromo Volcano, East Java, Indonesia. International Journal of Applied Engineering Research. Vol 12: 10867-10873. [5] Abidin, H. Z., Andreas, H., Gamal, M. (2004). The Deformation of Bromo Volcano (Indonesia) as Detected by GPS Surveys Method. Journal of Global Positioning Systems. 16-24.  [6] Zaennudin. (1994). Geological Map of Bromo-Tengger Complex, East Java. Bandung, Indonesia: Directorate of Volcanology.

Mount Tangkuban Parahu Overview Region Subang, West Java Latitude 6.77°S Longitude 107.6°E Summit 2084 m Elevation 6837 ft Primary Volcano Type Stratovolcano Last Known Eruption 2019 CE Literature and Analysis Eruptive History Geomorphology Geological Setting Structure Spatial Data Susceptibility Map Reference Eruptive History Geomorphology North of Bandung the morphology is determined by the Sunda-Tangkuban Perahu volcanic complex, including the large Sunda caldera and other remnants of older volcanism. The conspicuous flat summit of the active Tangkuban Perahu volcano, which formed inside the Sunda caldera, rises to some 2000 m. To the east and northeast, in the Bukanegara area, older volcanics are strongly affected by faulting and gravitational collapse. A relatively flat but dissected zone south and east of Tangkuban Perahu and and adjacaent to the town of Lembang is indicated as the Lembang surface or Lembang plain. Southwards, it is bordered abruptly by the Lembang fault scarp, running practically East-West. The normal faulting is ascribed to magmatic depletion as a result of the eruptions of the Sunda and Tangkuban Perahu volcanoes ([2] – [5]). Tangkuban Parahu is a volcano formed in the youngest phase of the continuation of the Sunda – Tangkuban Parahu volcanic system which has a long and complex geological history. Soetoyo and Hadisantono (2005) classified the volcanic rocks of Tangkuban Parahu into seven (seven) groups of volcanic units, ranging in age from old to young. These groups include the Tertiary Volcano, Pre-Sunda Volcano, Sunda Volcano, Kandangsapi Volcano, Dano Volcano, Bukitunggul – Manglayang Cone Group, and Tangkuban Parahu Volcano. Other non-volcanic rock deposits include lake deposits and fluviatile rocks. Because they are not covered by earlier volcanic deposits, volcanic rocks thought to be Tertiary in age are visible on the south-west lower slope and the northeast middle slope, generating a hill bulge morphology [6]. Based on tephrachronological analysis, the volcanism of the Sunda – Tangkuban Parahu Volcano Complex is grouped into 4 phases of volcanism, from old to young, namely Pre Sunda, Sunda, Tangkuban Parahu and Tangkuban Parahu. Two caldera successions produced pyroclastic flow deposits or Cisarua ignimbrites and Manglayang ignimbrites which are spread almost all over the slopes of Tangkuban Parahu. The Manglayang ignimbrites contain a number of accretionary lapilli, indicating that the paroxysm eruptions associated with the formation of the Sunda caldera were initiated by eruptions associated with phreatomagmatic systems [7]. The volcanism phase of Sunda volcano around 210-105 thousand years ago produced several lava flow units formed in the range of 210 thousand – 128 thousand years ago. These lavas are scattered on the northern slope of Tangkuban Boat [8]. Geological Setting According to Hartono and Koesoemadinata (1981) who compiled the stratigraphy of the North Bandung area, the oldest rocks exposed in this area are from the Cikapundung Formation, dated Lower Pleistocene, consisting of clasts, volcanic breccias, tuffs and andesite lava inserts. This unit is covered with an erosion field by the Cibeureum Formation of Upper Pleistocene-Holocene age, consisting of a repeating sequence of breccia-tuff with fragments of skoria-andesite-basalt and flint. Furthermore, the Upper Pleistocene-aged Kosambi Formation is deposited with lithologies of volcanic mudstone, volcanic sandstone, containing plant remains, locally found in parallel and cross-structured layers. Above this formation is deposited the Cikidang Formation which consists of columnar bridle-structured basaltic lavas, volcanic conglomerates, coarse, parallel-layered tuffs and volcanic breccias, this formation is Holocene in age. As the youngest deposits, loose materials of river deposits are deposited [9]. The oldest unit in this area is the Tertiary Sedimentary which consists of sedimentary materials. This unit is covered by the Pre-Sunda Volcanic Unit which consists of lava and pyroclastics. Then above the Pre-Sunda Volcanic Unit is deposited the SundaAndesite Unit aged Lower Pleistocene – Upper Pleistocene, Sunda Pyroclastic aged Late Upper Pleistocene, Tangkuban Parahu Andesite aged early Holocene, and Tangkuban Parahu Pyroclastic aged late Holocene [10]. The Quaternary Volcanic Zone produced the strato-type Tangkuban Parahu Volcano, which is one of the volcanoes that shape northern Bandung’s architecture. There are several eruption products from Post-Sunda Caldera in Figure 1 including, Tangkuban Parahu Pyroclastic Fall 1 (Tjp1), Tangkuban Parahu Lava flow 1 (Tl1), Ciceuri Lava flow (Cil1), and Tangkuban Parahu Pyroclastic Fall 3 (Tjp3) are the rock units discovered in Tangkuban Parahu [6]. Structure Regionally, the Bandung area is part of a group of Quaternary volcanoes bounded by a volcanic triangle. In the north-west there is the Sukabumi-Padalarang strike-slip fault zone, in the north-east the Cilacap Kuningan strike-slip fault zone and in the south a descending fault bordering the Southern Mountains. The west-east trending normal fault of the Southern Mountains became the line of emergence of the Southern Mountains, while in the north the Sunda Mountain was formed, which later collapsed and was followed by west-east trending thrusting by the Lembang Fault [12]. Spatial Data Volcanic features at Tangkuban Parahu. All volcanic features in the area of Tangkuban Parahu were created using available data as a base layer. The data was compared to the geological maps from Soetoyo (2005), to locate areas of the volcanic products. The volcanic features used are based on the youngest geological age. Tectonic features around Tangkuban Parahu. The tectonic features used consist of two structures around the Tangkuban Parahu faults and lineament features. The two shapefiles used as tectonic features are line files. Susceptibility Map The long-term susceptibility map serves as a crucial preliminary resource for predicting eruption locations spatially and lays the groundwork for further development into spatio-temporal dynamic maps or short term susceptibility maps. The places with a higher likelihood of a vent opening are indicated on the susceptibility map, assuming that an eruption takes place within this region. Wherever the greatest likelihood is 3×10-5. The existence of areas with high eruption susceptibility is around the three main craters (Ratu, Upas, and Domas). The large susceptibility value in the crater area is reinforced by the history of eruptions that have occurred such as phreatic eruptions in the Ratu crater.  Reference [1] Global Volcanism Program, 2024. Tangkuban Parahu (263090) in [Database] Volcanoes of the World (v. 5.2.1; 3 Jul 2024). Distributed by

Mount Batur Overview Region Bangli, Bali Latitude 8.2403°S Longitude 115.3775°E Summit 1711 m Elevation 5614 ft Primary Volcano Type Caldera Last Known Eruption 2000 CE Literature and Analysis Eruptive History Geomorphology Geological Settings Structure Reference Eruptive History Geomorphology The morphology of Mount Batur is closely related to the volcanic evolution that occurred and some are influenced by structural land conditions. The natural landscape of Mount Batur is composed of basalt andesite lava deposits. Lake Batur is one of the effects of the collapse that occurred in the Batur Caldera. This morphology was formed as a result of progressive volcanic activity that carried the rock inside until it finally collapsed into a caldera basin. After this subsidence occurred, several conditions such as Mount Abang were formed. Mount Abang, is part of the body of Mount Batur that did not collapse. In some places, the land is filled with lava covered by pyroclastic deposits [6]. Geological Settings The distribution of rocks produced from Mount Batur can be divided into 5 periods, namely, period I Tertiary period, period II Quaternary period (pre-caldera), period III caldera formation period I, period IV caldera formation period II, and period V post-caldera period. The oldest rocks exposed are the pyroclastic flow deposits of Bukit Jangkrik, these rocks are exposed in the southern part. The next rock that is exposed is the Cempaga Lava which is composed of olivine basalt, this rock is exposed slightly in the south. The younger rock is Tejakulak Lava which is exposed in the north, composed of porphyritic olivine basalt, bright grey, phenocrysts (about 40%) characterised by large euhedral – subhedral olivine with subhedral plagioclase (less than 2 mm) [7]. Structure The caldera of Mount Batur is enclosed from all directions, and is one of the largest and most beautiful calderas in the world [8]. The caldera rim ranges in height from 1267 m to 2152 m (Mount Abang Peak). Inside Caldera I, Caldera II is formed in a circular shape with a centre line of approximately 7 km. The base of Kaldera II is located between 120 – 300 m lower than Undak Kintamani (base of Kaldera I). Inside the caldera is a crescent-shaped lake. According to Van Bemmelen (1949), the lake is thought to have formed simultaneously with the formation of Kaldera II. Reference [1] Volcano.si.edu [2] Agastya, I. B. O., Diwyastra, P. D., Hespiantoro, S., & Ariana, D. (2023). SEBARAN DAN PROSES GEOLOGI PEMBENTUKAN LAVA TUBE KESAKSAK DI BATUR UNESCO GLOBAL GEOPARK. JURNAL GEOMINERBA (JURNAL GEOLOGI, MINERAL DAN BATUBARA), 8(1), 44-61. [3] vsi.esdm.go.id [4] Hidayati, S., & Sulaeman, C. (2013). Magma Supply System at Batur Volcano Inferred from Volcano-Tectonic Earthquakes and Their Focal Mechanism. Indonesian Journal on Geoscience, 8(2), 97-105. [5] Arif, A. S. (2016). Mount Batur Calderas as a Sacred Landscape in Bali. In 5th ACLA: Symposium on Sacred Sites, Cultural Landscape & Harmonizing the World of Asia. [6] Davis, W. M. 1921. “Review : Volcanoes of Eastern Bali Reviewed Work ( s ): DeVulkanen Goenoeng Batoer En Goenoeng Agoeng Op Bali by G . L . L .Kemmerling Review by : W . M . Davis.” 11(3):459–60 [7] Sutawidjaja, I. S., Chaniago, R., Kamal, S., and Modjo, W. S. (1992). Geological mapof Batur caldera, Bali, Indonesia. Volcanological Survey of Indonesia, Bandung  [8] Bemmelen Van, R.W. 1949. The Geology of Indonesia. Martinus Nyhoff, Netherland: The Haque.

Mount Rinjani Overview Region Lombok, West Nusa Tenggara Latitude 8.42°S Longitude 116.47°E Summit 3726 m Elevation 12224 ft Primary Volcano Type Stratovolcano Last Known Eruption 2016 CE Literature and Analysis Eruptive History Geomorphology Geological Setting Structure Reference Eruptive History Geomorphology Rinjani is a composite volcano protruding high up at the northern part of Lombok. It is mostly composed of young volcanic rocks. The Rinjani cone (3726 m asl) is the steepest and highest peak in the area, consisting of mostly loose materials with a crater on its summit. To the west of this volcano, there is a caldera containing water which is elliptical in shape and is called Segara. At the eastern part of Segara Anak Lake, there is a new volcanic cone called Barujari (2376m. asl), whereas to the west of it, there is another volcanic cone called Gunung Rombongan (2110 m asl). Both young volcanic cones are composed of lava flows and loose materials resulted from strombolian eruptions. Other volcanic cones in the surrounding area are Mt. Kondo (2914 m asl) at the SW part of the calderas, Mt. Sangkareang (2914 m asl.) at the NW part of the calderas, and Mt. Plawangan (2658 m asl.) at the NNE rim of the calderas. In the northeast flank of Rinjani, there is a plateau called Sembalun Lawang, which is located at an elevation of 1000 m above sea level. Compared to the northern flank, the southern flank of Rinjani is more perfectly developed, while at the eastern and western flanks other old volcanic bodies bound the developments of Rinjani [6]. Geological Setting Lombok island is located in the east Sunda arc on the crust of about 20-30km thick [7]. Pleistcone-Holocene volcanic complexes on the island are caused by the northern subduction of Australian plate beneath Eurasian plate [8-9]. Calk-alkaline Quaternary volcanoes develop on the basement of Tertiary sedimentary, volcanic, and intrusive rocks. The Pengulung Formation (Tomp) is the oldest group of rocks distributed in the southern part, dated to the Late Oligocene-Early Miocene. The Pengulung Formation overlies the Kawangan Formation (Tomk) which is Middle Miocene in age. Both formations were intruded by intrusive rocks composed of dacite and basalt (Tmi) of Middle Miocene age, resulting in alteration and mineralisation of sulphide ores and quartz veins in the intruded rocks. The two formations are unconformably overlain by the Late Miocene Ekas Formation (Tme). The three formations form the hilly area in southern Lombok. Furthermore, the three old rock units are unconformably overlain by the Lombok Volcanic Rock Group whose age ranges from Late Pliocene to Early Plistocene. The rock group consists of the Kali Palung Formation (TQp) which has the Selayar Member (TQs), Kalibabak Formation (TQb), and Lekopiko Formation (Qvl). The Lombok Volcanic Rock Group is unconformably overlain by Quaternary-aged inseparable volcanic rocks thought to originate from G. Pusuk (Qhvp), G. Nangi (Qhvn) and G. Rinjani (Qhvr). While the youngest rock unit is alluvium (Qa) which occupies the area around the coast [10]. Structure Tectonically, Lombok Island and its surroundings are influenced by the front arc rising fault system (subduction line) in the south and the Flores back arc rising fault system in the north. Likewise, according to Lumbanbatu (1998), the tectonics of Lombok Island is influenced by the South Java subduction line in the south (subduction line), the Flores Back Arc Rise Fault line in the north, the Lombok Strait Fault line in the west and the Alas Strait Fault line in the east. Furthermore, due to these active fault movements, Quaternary to Holocene sedimentary basins were formed in this area, which are bounded by the fault system [11]. Van Bemmelen (1949) interpreted the older basement of Solo Zone as the geanticline of East Java which re-appears in the western part of North Lombok. He suggested that the pattern of Java seems to end in this Island. The development of tectonic activity of Lombok was the result of an uplift, volcanic activity and intrusion. It is inferred that the oldest tectonic activity in Lombok took place in the Oligocene and was later followed by submarine volcanic activity of basaltic andesite composition, resulting in deposition of volcaniclastic rocks of Pengulung and Kawangan Formations. These two formations interfinger each other. The volcanic activity took place until Early Miocene and during Middle Miocene, a postmagmatic-activity occurred in the form of dacite intrusion into the Pengulung and Kawangan Formations [12]. Based on image (JERS-1) and landsat, the fracture dan fault structures show south-east directions, caused by a north-south tectonic compression of Sunda arc (in Java, Bali, Lombok and Flores). This lateral compression is initially formed by simetrical and un-simetry folds and faults, followed by transcurrent faults, which show twin conjugates normal faults. A structural level concept represents the study area is part of upper structural level, having brittle rocks, showed by a ”rose diagram” frequence and a cumulative length of the northwest-southeast fault systems indicating subsurface permeable rocks of Sembalun, Propok and Rinjani volcananics [13]. Reference [1] Volcano.si.edu [2] Vidal, C. M., Komorowski, J. C., Métrich, N., Pratomo, I., Kartadinata, N., Prambada, O., … & Surono. (2015). Dynamics of the major plinian eruption of Samalas in 1257 AD (Lombok, Indonesia). Bulletin of Volcanology, 77, 1-24. [3] Abdul-Jabbar, G., Rachmat, H., & Nakagawa, M. (2019). Temporal change of Barujari Volcano magmatic process: Inferred from petrological study of erupted products since AD 1944. In Journal of Physics: Conference Series (Vol. 1363, No. 1, p. 012030). IOP Publishing. [4] Rachmat, H. (2012). Volcano Tourism of Mt. Rinjani in West Nusa Tenggara Province, Indonesia: a Volcanological and Ecotourism Perspective. Berita Sedimentologi, 25(1), 47-54. [5] Green rinjani.com [6] Kusumadinata, K., (1979), Data Dasar Gunungapi Indonesia. Catalogue of References on Indonesian Volcanoes with Eruptions in Historical Time. Direktorat Vulkanologi, p. 424-438.  [7] Curray, J. R., Shor Jr, G. G., Raiit, R. W. and Henry, M., (1977). Seismic refraction and reflection studies of crustal structure of the eastern Sunda and western Banda arcs. J. Geophys. Res., 82: 2479- 2489. [8] Cardwell, R. K. and Isacks, B. L, (1978). Geometry of the subducted