Over the World

MUD VOLCANO AND TOURISM: Geo_Tourism

Lusi, Sidoarjo, Indonesia

Mud volcanoes are not extraordinary, they are about a thousand located in several volcanic areas in the world (i.e.: Borders of the Black sea and Caspian sea in Eastern Europe, Azerbaijan, Yellowstone National Park).

Indonesian islands, which are definitively on one of the most highly active area in the world, are not escaping to this volcanic phenomenon.

Lusi mud volcano initiated erupting on 29 May 2006, in the regency of Sidoarjo, on the North East coast of Java, 35 kilometers away from Surabaya, the second largest city of Indonesia.

LUSI and Other Mud Volcanoe

• • • Awang

      • • 1-PAPER 2008

An unexpected eruption of mud and fluids took place on 29^th May 2006 in the Porong area, Sidoarjo, East Java (Figures 4, 6, 7). The eruption site was named LUSI (abbreviation of “Lumpur Sidoarjo” or Sidoarjo mud). Based on the characteristics of eruption and related geologic data, LUSI was concluded as eruption of mud volcano. The eruption is still taking place at the time of this writing (March 2008). The volumes of erupted mud increased from the initial 5000 m³/day in early stage to 120,000 m³/day in August 2006 and peaked to 170,000 m³/day in September 2006 and reached the record-high level of 180,000 m³/day in December 2006 (Mazzini et al., 2007). LUSI was still active in December 2007 expelling more than 80,000 m³/day. As of December 2007 the total volume of expelled mud was estimated at 1 billion cubic feet, covering an area of 2.5 square miles, burying eleven villages and displacing at least 16,000 people. Transportation and power transmission infrastructure has been damaged extensively in the area. It is expected that the mud eruption will last for years to come and the area will experience a significant depression, forming a large caldera.

LUSI is one of numerous mud volcanoes in the eastern part of the Kendeng Zone/Depression. Mud volcanoes occur at many locations in the Kendeng Zone from Bledug Kuwu at the western border of the zone to the submarine mud volcanoes in the Madura Strait. Other recognized mud volcanoes close to LUSI (variably active, extinct, or dormant) are Porong, Kalang Anyar (Sidoarjo), Gunung Anyar (near Surabaya), Socah (Bangkalan, Madura), Wringin Anom (border of Gresik-Mojokerto), Semolowaru, Pulungan, and Sedati (Sidoarjo). Based on historical chronicles, folklore, and geologic data, recent paper by Satyana (2007) elaborated the presence of mud volcanoes complex erupted in historical time during the periods of Jenggala and Majapahit Kingdom in Indonesia (12^th-15^th century). He indicated the presence of mud volcanoes in this period in a zone called Tunggorono – Jombatan – Segunung – Canggu - Bangsal in Jombang-Tarik, mostly in Sidoarjo area, as long as 25 kms.

The Kendeng Zone is one of the youngest tectonic features in the eastern Java area. It was formed virtually at the early to late Pliocene (Lunt et al., 1996). It was part of a continuously subsiding basin from Miocene to the end of the middle Pleistocene. Late Miocene and older sediments in the Kendeng Zone are typically thick, interbedded mudstones and volcaniclastic sands. The marls and limestones of the Lower and Upper Kalibeng Formation were deposited in almost entirely marine environment during the Pliocene. At the time, volcanic activity probably began in the volcanic arc to the south (Wilis and Lawu volcanoes). This activity influenced the western part of East Kendeng Zone at the beginning of the Pleistocene. Here early Pleistocene Pucangan volcaniclastic sediments conformably above the Upper Kalibeng. Above this in conformable contact occur volcanic sandstones of the middle Pleistocene Kabuh and then the Notopuro Formation. During the early Pleistocene, marine blue clays of Pucangan were deposited in the east where finally volcanic deposits prograded (Duyfjes, 1936). The volcanic material was initially deposited in a marine environment in the west, but filled the basin very fast, so that sediment input near the volcanic centers soon exceeded the accommodation. In the east, where volcanic sediments arrived later, the volcaniclastic input was not sufficient to fill the basin until the late Pliocene.

The gravity data of the Kendeng Zone shows strongly negative anomalies indicating considerable depth to the basement in the Kendeng Zone. The Kendeng Zone is the deepest part of the Java’s depression from Bogor-North Serayu-Kendeng-the Madura Strait. The Kendeng Zone is strongly folded and sometimes heavily faulted in the western part. Structuring is very recent and is probably still active. The sudden change of the Brantas River in the time of King Airlangga (11^th century) was due to the Recent deformation of fold underlying the river (Satyana, 2007). Fold axes in this area are oriented in E-W direction; an indicator that the adjacent and parallel volcanic chain is, at least in part, is responsible for compression. In the east, south of Surabaya where numerous mud volcanoes occur, the folds are nearly lost under recent alluvium and even Pleistocene rarely crops out.

The Kendeng Depression/Zone is the best elisional basin in Indonesia therefore, numerous mud diapirs and mud volcanoes occur here. Young tectonic feature, subsided basin, compressed, very thick young sediments deposited rapidly in relatively short period, and thermally significant due to nearby volcanic arc make the Kendeng Depression to be elisional. High sedimentation rate initiated during Upper Miocene – Early Pliocene time causing deposition of a very thick highly overpressured sedimentary succession. Clayey and silty sediments interbedded with sand beds contain great amount of fluids. The presences of overpressured sediments, less dense plastic shale succession underlying more dense beds and saturated with the fluids, and high tectonic activity favors the mud diapirs and mud volcanoes development in the region. Mud diapirism and mud volcanism apparently plays important role in the regional geology of the area. They also critical in the formation of folds at shallow depth. Seismic sections show that many folds in the Kendeng Zone are cored by diapirs.

Presently erupting-LUSI mud volcano provides good opportunity to know the origin of mud volcanoes in the Kendeng Depression. All other active, extinct, or dormant mud volcanoes in the Kendeng Depression might occurred several hundreds, thousands, or several million years ago. Historical chronicles (Kitab Pararaton – Book of Kings) during the Majapahit Kingdom from 13^th to 15^th century show the occurrences of natural disasters may be interpreted as mud volcanoes eruption (Satyana, 2007). The main Kendeng Depression has existed since 5 Ma, it has been compressed since then. It can be expected that mud volcanoes in the Kendeng Depression were triggered by tectonics and seismicity as most mud volcanoes in the world originated. LUSI mud volcano, began erupting on 29 May 2006 however, can not provide straightforward explanation on its origin due to possibility that LUSI may relate to drilling of exploration well located 200 meters away from LUSI.

The origin of LUSI mud volcano has been a matter of debate. Three trigger mechanisms have been proposed : (1) tectonic re-activation by the May 27^th 2006’s Yogyakarta earthquake, (2) well drilling operations (Banjar Panji-1 well by Lapindo Brantas) in progress near the initial eruption site at the time of the eruption, and (3) a combination of earthquake and drilling operations. Earthquake trigger was argued among others by Mazzini et al. (2007) and Svensen et al. (2007). Drilling operations trigger was argued among others by Davies et al. (2007). Earthquake trigger was challenged by Brumm et al. (2007). Mori et al. (2007) indicated that the trigger of LUSI may a combination of both the 27^th May 2006’s Yogyakarta earthquake and drilling of Banjar Panji-1. The controversy on the origin of LUSI has complicated the legal aspect of LUSI in the court.

Based on geochemical and field results, Mazzini et al. (2007) proposed a mechanism that LUSI mud volcano eruptions started following the May 27^th 2006’s Yogyakarta earthquake due to fracturing and accompanied depressurization of > 100º C pore fluids from > 1700 meters depth.

This resulted in the formation of a quasi-hydrothermal system with a geyser-like surface expression and with an activity influenced by the regional seismicity. Brumm et al. (2007) challenged this idea since the earthquake is too distant and too small to trigger the LUSI eruption, and plotting of LUSI to cross plot of Manga and Brodsky (2006) which is a statistic cross plot between occurred earthquakes and related liquefaction and mud volcanoes show that LUSI plotting is out of general trend. Brumm et al. (2007) also argued that in the past 35 years, tens to hundreds of other earthquakes caused stronger ground shaking at the site of the eruption but why did not trigger an eruption.

Davies et al. (2007) suggested that LUSI eruption appears to have been triggered by drilling of overpressured porous and permeable limestones at depths of ~2830 m below the surface.

They proposed that the borehole provided a pressure connection between the aquifers in the limestones and overpressured mud in overlying units. As this was not protected by steel casing, the pressure induced hydraulic fracturing, and fractures propagated to the surface, where pore fluid and some entrained sediment started to erupt.

It is not the aim of this paper to examine in detailed the mechanism responsible triggering the LUSI mud volcano. However, there are facts indicating that the Yogyakarta earthquake was significant triggering the LUSI mud volcano eruption. The facts are hereafter :

(1) drilling operations sequence show that partial loss of drilling mud in Banjar Panji-1 well occurred ten minutes after the earthquake,

(2) total loss in the well occurred after several the earthquake’s aftershocks,

(3) mud erupted two days after the earthquake,

(4) early eruptions of hot mud and salt water occurred in several localities forming the SW-NE trend parallel with the main structural trend of faults or fractures in this area,

(5) mud eruption never expel from the well, it is 200 meters to the southwest of the well and engineering test showed that there is no communication between the site of mud eruption and the wellsite,

(6) LUSI lies within major faults (Watukosek Fault) trending SW­NE from Penanggungan volcano to the Strait of Madura, the fault becomes the sites of extinct or dormant mud volcanoes of Kalang Anyar, Pulungan in Sidoarjo area, Gunung Anyar in Surabaya area, and Socah in Bangkalan, western Madura area,

(7) the occurrence of a fracture in the wellsite hundreds meters long and tens of centimeters wide trending NE-SW a few days after the eruption

(8) there was a decrease in gas flow rate at nearby Carat well at about the time of the Yogyakarta earthquake took place,

(9) the Yogyakarta earthquake re-activated the Semeru volcano three days after the earthquake by increasing its surface temperature and erupting volcanic ash (NASA’s Terra satellite data),

(10) the Yogyakarta earthquake was recorded 34 seconds after the main shock in Ujung Pangkah waters to the northwest of Surabaya and its energy affected the seismic recording which was being surveyed at the area at the time of earthquake occurred in Yogyakarta,

(11) the energy propagation of the earthquake was mainly eastward and northeastward as shown by the trend of its aftershocks and the areas affected,

(12) regional satellite data show the presences of major faults and fractures from Yogyakarta to Sidoarjo area in a right-stepping pattern,

(13) there is a positive correlation between mud eruption rates of LUSI and swarms of earthquakes measured 300 kms around the site, high rates followed occurrences of earthquakes,

(14) recent deuterium isotope data of erupted water showing a mixing with static magmatic fluids from depth deeper than 20,000 feet, indicating the presence of deep basement faults or fractures within the site as the conduits, (15) the sudden bending of railway to south of the eruption site occurring after the May 27^th earthquake is exactly at the crossing between the Watukosek Fault and the railway and in line with the bending of the Porong River, confirming that the fault was re-activated by seismic activity.

On the other hand, argument of Davies et al. (2007) based on the assumption that Banjar Panji-1 total depth in porous Kujung aquifer limestone is not supported by the well data. Well logging data show no direct evidence that the Kujung Formation has been intersected in the borehole.

The deepest cuttings did not reveal the presence of any carbonate, and calcimetry data indicate only 4 % calcite with no significant increase or changes.

The presence of Oligo-Miocene Kujung Formation in this area is also mis-conception. Based on the available data and facts explained above, the idea that LUSI eruption is triggered entirely by drilling is inconclusive. Earthquake-related tectonic re­activation of fault where the well is located and the elisional condition which has been critical for mud volcanism in the area may play significant role for the birth of LUSI mud volcano.

In terms of morphology, LUSI mud volcano is of the type of combination between swamp-like area and crater muddy lake. It is obviously stage-3 development (on eruptive phase). Similar type of morphology is shown by Kalang Anyar mud volcano.

Whereas, Pulungan, Gunung Anyar, and Socah mud volcanoes show morphology of classic conic volcanic edifice. The stages of those mud volcanoes are as follows : Kalang Anyar (dormant, ­stage 3 to 4), Pulungan (extinct –stage 4), Gunung Anyar (extinct –stage 4), Gresik (dormant-stage 3), Socah (dormant –stage 3 to 4), Porong (extinct – stage 4). Collapse of mud volcano crater of Porong is obviously shown by successive concave horizons (Figure 7).

Bledug Kuwu Mud volcano Complex

Link Setyana (2008): https://sites.google.com/site/lusilibraryhardi2010/awang/1-paper-2008

“Bledug” means the sound like cannon-fire. Complex of Bledug Kuwu mud volcanoes are located to the east of Semarang city and 20 kms to south of Purwodadi town, Central Java (Figures 4, 6, 7). Geologically, they are located at the boundary area between North Serayu and Kendeng Depressions.

There are some mud volcanoes in this area (Bledug Kuwu, Bledug Kesongo, Bledug Kropak, and several others). Kuwu is the largest of a number of active mud volcanoes in the area.

The morphology is a set of vents in a flat area of quick-sand like clay, with a dried mud crust. Eruptions vary in frequency but generally occur more than once a minute, as a burst of warm gas spraying mud in all directions. It is assumed that mud flows more slowly and gradually, but is kept liquefied by the escaping fluids and gases (Burgon et al., 2002).

The morphology type is a combination of swamp-like area extending for large territory and crater muddy lake. The phase of mud volcano is eruptive to post-eruptive (stage 3 to 4). The presence of quick-sand indicates the subsidence of mud volcano area.

The Kuwu mud volcano cluster covers about 45 hectares. The biggest vent can erupt materials as high as 5.3 meters with expelled mud reaching out for a diameter of about 9 meters. At the main Kuwu site the big mud volcano usually erupts four or five times a minute.

The salinity and turbidity of the mud volcanoes mean that there is no vegetation or animal life in the area of the eruptions. The gas expelled is non­flammable, reported as CO2, with traces of H2S.

Local people commercially process the expelled water to extract salt for cooking. It is also reported that the mud sometimes carries rock fragments and fossils, but no details are available. Samples of the mud taken by Burgon et al. (2002) proved to be barren of any calcareous micro or nannofossils suggesting mildly acidic conditions.

The temperature of the big mud volcano ranges from 28-30ºC, while the small mud volcano is reported to have a temperature of only 15-16ºC, a surprising feature hard to explain or verify. Small mud volcano has more water content (lower density), which might account for its more frequent eruptions and lower temperature.

Seismic sections across these mud volcanoes show disturbed zones from top of the Kujung Formation up section through the top of Wonocolo Formation to the surface. Bledug Kesongo is obviously characterized by collapse structure with upward concave horizons along the disturbed zone indicating the stage-4 of mud volcano subsidence.

The Bledug Kuwu disturbed zone is chaotic mixture of upward convex and concave reflectors indicating stage-3 to stage-4. The mother beds of diapirs and mud volcanoes are considered the lower part of Late Miocene Wonocolo shales. This is confirmed by fossil content of mud materials. However, seismic sections show that the source of mud may also come from Early Miocene Tuban shales.

Bleduk Kuwu, Purwodadi, Indonesia

http://discover-indo.tierranet.com/Volcano08.htm

Tourist to visit the Mud Volcano

Preview: bleduk_kuwu.jpg View Download

Bledug Kuwu in Grobogan, Central Java, has been a tourist destination for decades. For local people, bledug means explosion and kuwu or kuwur means scattered.

People visit the site to watch the mud volcano, which erupts every three minutes, resulting in beautiful formations. Located several minutes by car from Blok Cepu mining site, Bledug Kuwu is somehow identical to the mudflow in Sidoarjo, East Java. If Sidoarjo's mudflow has displaced nearby residents and brought misery to the people, Bledug Kuwu has helped local people earn money.

People living near this tourism site make money by selling salt to visitors. The salt is harvested from volcanic sediment that is dried in an open field. Legend has it that the explosion comes from a tunnel that connects the site to the mystical "Laut Selatan" or Indian Ocean. The tunnel is a passage for a mystical knight, Joko Linglung, and allows him to move between Laut Selatan and the Medang Kamulan Kingdom, the area of which includes today's Grobogan. Joko Linglung made the passage when he transformed into a huge dragon to demonstrate his supernatural powers to Aji Saka, the king of Medang Kamulan.

from The Jakarta Post. Photos by Tarko Sudiarno

Borneo

http://lostborneo.wordpress.com/tag/mud-volcano/

Other than lazing around and swimming and snorkeling, the one thing that you must do is to soak in a mud volcano.

Mud volcanoes are formed when natural gas builds up enough pressure to escape along cracks in the earth’s surface, carrying with it mud, water, and rocks. Pulau Tiga is believed to have been formed by the eruption of several mud volcanoes.

There are 3 volcanoes all together. The last violent eruption occurred in 1941 when the eastern volcano erupted. The eruption was heard as far as 160 km away and almost 30 hectares of forest was smothered with boiling, hot liquid mud.

Thankfully, the volcanoes are now largely dormant. Every few hours, bubbles of gas rise to the surface and splatter cold mud over the surrounding vegetation. Near to the mud volcanoes are mud pools, not unlike those that buffaloes wallow in. The nearest one is about 30 minutes trek through the jungle.

You should do like the buffalo does and soak in the mud. The mud feels cool and some people believe that their skin feels smoother after a natural mud spa. There are not many places in Malaysia where this is possible and it is a unique and fun experience.

Getting out of the mud pool, it is a race against time to get back to wash yourself as the mud begins to harden on your body and you start to walk, look and feel like a mudman. Don’t forget to take those once in a lifetime mudman photos

Columbia

Written by Wild Asia on 7 Jun 2005

Ditinjau oleh Hardi Prasetyo, Untuk Lusi Library: Knowledge Managment, Aspek Turisme

Suatu mud volcano, adalah nama yang diberikan, suatu padanan dari gunung api yang normal (normal volcano) dan umum kita ketahui, kecuali daripada ia mengeluarkan lava panas atau asap, ia memuntahkan lumpul. Dalam kaitan ini is bukanlan suatu gunungapi yang sebenarnya.

A mud volcano, as the name suggested, is similar to the normal volcano we know off except that instead of spewing out hot lava or ash, it expels mud. In that sense, they are not true volcanoes.

Lumpur umumnya dingin dan dapat berasal dari kedalaman lebih dari 3 km. Sangat sedikit mud volcano berasosiasi dengan panas dan terkait hal tersebut cenderung semburan lumpur panas dangkal yang disemburkan kepermukaan.

The mud is usually cold and can originate from depths of up to 3 kilometres. Very few mud volcanoes are associated with heat and these tend to be shallow hot mud erupting to the surface.

Mud volcano umumnya didapatkan pada daerah yang kaya dengan minyak dan gas bumi (areas rich in oli and natural gas), terkadang kenampakannya terdapat sepanjang zona-sona lemah di kerak Bumi (along zones of weakness in the Earth's crust).

Mud volcanoes are commonly found in areas rich in oil and natural gas, often appearing along zones of weakness in the Earth's crust.

Mud volcano eksis pada semua benua dan samudera, namun lebih banyak terkonsentarasi sekitar Laut Kaspia.

They exist in all continents and in all oceans, but their largest concentration is in and around the Caspian Sea.

Lebih setengahnya dari mud volcano di dunia terdapat di dalam atau di Azerbaijan Timur dimana ia berasosiasi dengan lapangan-lapangan minyak dan gas bumi. Di daerah lain, ia juga dapat berasosiasi dengan volkanisme yang normal (normal volcanism) seperti di Yellowstone atau yang sedikit mengalami pergerakan tektonik (obsure tectonic movment) seperti di daerah rainforest dari Pulau Tiga dan Tabin di Sabah.

More than half of the World's mud volcanoes are in or off Eastern Azerbaijan where they are associated with oil and gas fields. In other regions, they can also be associated with "normal" volcanism such as in Yellowstone or with obscure tectonic movements such as in the rainforests of Pulau Tiga and Tabin in Sabah.

Walaupun mud volcano tidak indah untuk dipandang, namun dia sangat menyenangkan untuk dilihat (definietely fun to look at). Bualan lumpur yang konstan (constant bubbling mud), secara pediodik membuat ledakan atau semburan kecil yang dapat didengar dari jarak kejauah. Ia juga mempunyai perbedaan dalam ukuran, berkisar dari beberapa sentimeter sampai pada lebar beberapa kilometer. Mud volcano juga dapat berbentuk sebagai kolam kecil (smaal pools) sampai bukit dengan ketinggian sampai bebeapa ratus meter.

Although mud volcanoes may not be pretty in sight, they are definitely fun to look at. The constant bubbling mud, periodically making small explosions can be heard from a fair distance away. They also come in different sizes, ranging from a few centimetres to a few kilometres wide. They can form small pools to hills up to a few hundred metres in height.

Asalmula mud volcano

The origins of mud volcanoes

Berikut ini adalah kenampakan utama yang umum dari mud volcano:

Following are the main common features of mud volcanoes:

1. Umumnya terdapat di daerah dengan aktivitas gempabumi (earthquake activity), berasosiasi dengan jalur perlipatan Kenosoik (Cenozoic fold belt)

They are usually found in areas of earthquake activity, associated with Cenozoic fold belts.

1. Berasal dari lapisan-lapisan lempung yang tebal (thick clay beds), pada kedalaman lebih dari 3 km

They originate from thick clay beds at depths of up to 3 kilometres.

1. Ia merupakan even geologi yang muda

They are geologically young

1. Ia umumnya menyembur sepanjang patahan geologi (geological faults)

They usually erupt along geological faults.

1. Terdapat bualan air asin, gas umumnya metan dan terkadang minyak..

They bubble salt water, gas (usually methane) and sometimes oil.

1. Ia terdakang menghasilkan bongkah dari batuan (produce blocks of rock) yang berasal dari kedalaman yang besar, menyerupai dengan gunung api yang sebenarnya.

They often produce blocks of rock from great depths (like real volcanoes).

Jika mud volcano mengandung minyak dan gas, ia sering didapatkan dekta dari daerah produksi minyak (petroleum producing areas).

Bila inti pemboran dari gunung lumpur di uji dan dibandingkan dengan lumpur di permukaan, sumbur selalu bersaam dengan lumpur-lumpur yang tidak normal dengan densitas yang rendah (abnormal low density) untuk kedalamnya ia terkubur (depth of burial), dan ia selalu mempunyai tekanan yang tinggi (highly pressure).

Karena itu, overpressure merupakan bagian yang pentung di dalam asal mula mud volcano.

As mud volcanoes emit oil and gas, they are often found in petroleum producing areas. When the drilled core of the volcanoes are tested and compared to the mud from the surface, the source usually coincides with clays of abnormal low density for their depth of burial, and they are always highly pressured. Thus, overpressure is an important clue as to the origin of mud volcanoes.

Beberapa gagasan tentang apa penyebab dari overpressure:

There are several ideas on what causes these overpressures:

Lapisan-lapisan lempung (clay beds) umumnya diendapkan dengan sngat cepat pada ujung dari benua (edge of the continent) oleh dltas sungai besar (large river delta) atau oleh longsoran gaya berat (gravity sliding) ke bawah ari lereng benua (continental slope). Beberapa diantaranya percaya bahwa urut-urutan lumpur dikubur sangat cepat, sehingga ia tidak mempunyai waktu untuk memuntahkan kandungan air yang ada di dalamnya, selanjunya menyebabkan tekanan berlebih (overpressure).

Yang lainnya berpikir bahwa pembentukan dari minyak dan gas bumi (generation of oil and gas) pada kedalaman menyeabkan tekanan meningkat ke atas. Namun terdapat bukti yang potensial bahwa semua dari mekanisme tersebut dan itu tampaknya menjadi suatu kombinasi mekanisme yang memberikan dampak pada lempung dan arti pentingnya dapat bervariasi dari satu tempat ke tempat lainnya.

The clay beds are usually deposited very rapidly at the edge of the continent by large river deltas or by gravity sliding down the continental slopes. Some believe that the clay sequences are buried so quickly that they do not have the time to expel all the excess water in them, thus causing the overpressure.

Others think that the generation of oil and gas at depth causes the pressures to go up. However, there is potential evidence for all these mechanisms and it is very likely that a combination of the mechanisms affects the clay and their importance can certainly vary from area to area.

Apa penyebab semburan mud volcano?

What causes them to erupt?

Menurut John Woodside, pakar geologi dari Universitas Free di Amsterdam dan salah satu pemimpin peneliti didalam Projek Medmud, mud volcano dapat dilihan sebagai katub tekanan terbuka di dalam kerak bumi (as open pressure valves in the earth's crust). Lempeng-lempeng tektonik (tectonic plates) dimana membentuk permukaan dari planet kita ia bergerak setiap saat.

Sebagai hasil, ia memproduksikan jumlah yang besar dari sampah dalam bentuk sedimen yang dibangung pada rekahan antara dua lempeng dan secara gradual meningkatkan tekanan di bawahnya.

Pada beberapa titik tekanan menjadi demikian besar sehingga gas, air dan pasir di tekan keluar - lahirlay suatu mud vulcano (a mud volcano is born).

Mud volcano selalu berasosiasi dengan gempabumi (mud volcano are usually associated with earthquackes) dan juga terapat sepanjang patahan-patahan geologi (geological faults). Salah satu insiden tersebut adalah mud volcano Piparo di Trinidad yang menyembur liar (erupted violently) beberapa tahun yang lalu dimana bersamaan dengan goyangan dan gunjangan dan merusak rumah didekatnya.

According to John Woodside, geologist at the Free University in Amsterdam and one of the leading researchers in the 'Medmud' Project, mud volcanoes can be seen as open pressure valves in the earth's crust.

Tectonic plates which form the surface of our planet rub together all the time. As a result, they produce large amount of debris in the form of sediment which builds up on the crack between two pates and gradually increases the pressure beneath it.

At some point the pressure becomes so great that gas, water and sand is pushed out - a mud volcano is born.

Mud volcanoes are usually associated with earthquakes and also occur along geological faults. One such incidence is Piparo mud volcano in Trinidad that erupted violently a few years ago which coincide with a tremor that shook and destroyed a nearby house.

Apakah ia membahayakan?

Are they dangerous?

Semburan dari mud volcano sendiri adalah liar dan kebanyakan menjauhi pusat semburan bubble yang melemah, tapi ia dapat bahaya ketika suatu mud volcano secara tiba-tiba menginjeksi menyemburkan gas dalam jumlah yang besar. Terdapat suatu resiko dari asphyxiation untuk manusia dan binatan yang ada didekatnya.

Juga terdapat resiko dari keterbakarnya bualan gas dan beberapa dapan menyebabkan longsoran tanah dan pembendungan sungai. Namun, hanya beberapa mud volano, seperti satunya pada pula mud volcanic di lepas pantai konta Baku, yang diketahui untuk ledakan gas panas, dan menyebabkan kecelakaan fatal pada manusia sedikitnya tika kali sejak tahun 1900.

Eruptions of mud volcanoes are seldom violent and most just bubble away gently, but they can be dangerous when a mud volcano suddenly ejects a large amount of gas suddenly. There is a risk of asphyxiation for humans and animals in the immediate vicinity.

There is also the risk of gas plume catching fire and some can cause landslides and river damming. However, only a few mud volcanoes, such as the ones on mud-volcanic islands off Baku city, are known for hot gas explosions, and have caused human fatalities at least three times since 1900.

Kemanfatan

Benefits

Sebagi tambahan menjadi pertenda dari endapan minyak dan gas bumi (markers of oil and gas deposits), mud volcano digunakan sebagai sumer air panas, gas bumi (natural gas), dan lempung. Di pantai Laut Azov, dipercaya bahwa lumpur mengandung kualitas penyembuhan (medical qualitas) dan digunakan pada Spa lokal. Namun, kemanfaatannya untuk binatang, belumlah diselidiki.

In addition to being markers of oil and gas deposits, mud volcanoes are used as source of hot water, natural gas, and clay. On Azov Sea coasts, it is believed that their mud contains medical qualities and is used in local spas. Its benefits to animals however, have not been studied.

The study of mud volcano helps geologists understand complex processes that occur during the deposition and deformation of sediments. It also helps them to better understand the generation and migration of oil and gas in the sediments.

Compiled by Wild Asia team.

References:

• Yassar, N.A. http://www.science.uwaterloo.ca/earth/waton/f912.html

• http://www2.rnw.nl/rnw/en/features/science/040601rf.html

• http://dinets.travel.ru/mudvolcs.htm