Lusi Mud Research Articles

The Lusi drone: A multidisciplinary tool to access extreme environments

Extreme and inaccessible environments are a new frontier that unmanned and remotely operated vehicles can today safely access and monitor. The Lusi mud eruption (NE Java Island, Indonesia) represents one of these harsh environments that are totally unreachable with traditional techniques. Here boiling mud is constantly spewed tens of meters in height and tall gas clouds surround the 100 m wide active crater. The crater is surrounded by a ∼600 m diameter circular zone of hot mud that prevents any approach to investigate and sample the eruption site. In order to access this active crater we designed and assembled a multipurpose drone.The Lusi drone is equipped with numerous airborne devices suitable for use on board of other multicopters. During the missions, three cameras can complete 1) video survey, 2) high resolution photogrammetry of desired and preselected polygons, and 3) thermal photogrammetry surveys with infra-red camera to locate hot fluids seepage areas or faulted zones. Crater sampling and monitoring operations can be pre-planned with a flight software, and the pilot is required only for take-off and landing. A winch allows the deployment of gas, mud and water samplers and contact thermometers to be operated with no risk for the aircraft. During the winch operations (that can be performed automatically), the aircraft hovers at a safety height until the tasks controlled by the winch-embedded processor are completed. The drone is also equipped with GPS-connected CO2 and CH4 sensors. Gridded surveys using these devices allowed obtaining 2D maps of the concentration and distribution of various gasses over the area covered by the flight path.The device is solid, stable even with significant wind, affordable, and easy to transport. The Lusi drone successfully operated during several expeditions at the ongoing active Lusi eruption site and proved to be an excellent tool to study other harsh or unreachable sites, where operations with more conventional methods are too expensive, dangerous or simply impossible.

Modelling of gas generation following emplacement of an igneous sill below Lusi, East Java, Indonesia

The Lusi mud eruption started in 2006 and is located near the Arjuno-Welirang volcanic complex in Northeastern Java. Lusi is characterized by the eruption of aqueous vapor, CO2, and CH4 in addition to mud breccia and boiling water. However, the ultimate driving force for the eruption remains unclear. Here we investigate if Lusi could have been driven by the heat released from a deep-seated igneous sill originating from the neighboring volcanic arc. We have used a 1D thermal model to calculate the production of CO2 from thermally matured organic matter in the contact aureole of a hypothetical 150 m thick sill. The sill is tentatively emplaced at 1100 °C at 4.5 km depth within the organic-rich Eocene Ngimbang Formation. The carbon gas produced from the thermal perturbation reaches a peak of 1357 kg/m2/y CO2 equivalents shortly after sill emplacement, stressing the efficiency of organic matter transformation in contact aureoles. Our simulations show that during the first 1000 years after emplacement, 53.5 ton CO2/m2 is produced in the contact aureole. When scaled to a sill size of 150 m × 25 km2, i.e., a sill volume of 3.75 km3, the aureole has the potential to generate a total of 1350 Mt CO2 during the first 1000 years, with a peak generation of about 34 Mt CO2/y. We conclude that contact metamorphism in our hypothetical geological scenario generates CO2 in the gigaton range and represents a plausible source for the Lusi gas.

Constraints on density changes in the funnel-shaped caldera inferred from gravity monitoring of the Lusi mud eruption

From its inception May 29, 2006, the Lusi mud eruption has continuously erupted fluids, boiling mud and clasts through large active vents approximately 100 m in diameter. In 2016, we conducted a Dynamic Gravity survey (DG) using a network built over four locations and two Continuous Gravity-monitoring (CG) experiments to monitor the eruption activity. The CG was done for 8 days from June 2nd to June 10th, and for 9 days from August 20th to August 29th, 2016. Atmospheric pressure and atmospheric temperature variations were recorded during each experiment to constrain potential environmental effects, and Earth and oceanic tide effects were removed from gravity signals (CG and DG). Atmospheric pressure effects were removed from CG gravity signals. At the station, closest to the hydrothermal pond, the DG survey results show a gravity increase of ∼0.009 mGal month−1, which we interpret as the growth of the mud edifice in the central area. CG-monitoring shows that gravity variations occur at a period of 12–13 h, with amplitudes reaching up to 0.020 mGal. We interpret this as relating to density variation of the rising mud mixture (fluids + coarse mud + clasts). The observed 12–13 h period variations appear to indicate that tides may have some control on the density change of rising mud mixture by triggering the release of gas trapped at depth. Our 3D gravity results around the Lusi vents show that density variations range from 100 kg m−3 to 775 kg m−3. Similarly, vent diameters better constrain density contrasts occurring within the caldera zone, which is more likely to range between 400 and 450 kg m−3, and is equivalent respectively to 27% and 31% of gas ratio change over time.

Lusi hydrothermal structure inferred through ambient vibration measurements

The spectacular Lusi mud eruption started in northeast Java, Indonesia, the 29th of May 2006 following a M6.3 strike slip seismic event. After the earthquake several mud pools aligned along a NE-SW direction appeared in the Sidoarjo district. The most prominent eruption site was named Lusi. Lusi is located ∼10 km to the NE of the northernmost cone of the Arjuno-Welirang volcanic complex with which it is connected by the Watukosek Fault System. In this study, we applied the HVSR method, which is a common tool used for site effect investigations as well as to infer buried structures and reconstruct sub-surface geology. The method is based on the ratio of the horizontal to vertical components of ground motion and it generally exhibits a peak corresponding to the fundamental frequency of the site. Spectral ratio results highlight a fundamental frequency band between 0.4 and 1.0 Hz in the Lusi neighborhood. We interpret these peaks as related to the velocity lithological contrast at depth between alluvial deposits and bluish grey clay. Our analysis also highlights the presence of a “depocenter”, characterized by fundamental frequency up to 0.3 Hz, which is interpreted as the subsidence caused by withdrawal of mud and fluids from depth (as also shown by the comparison of the HVSR results with gravimetry data). Moreover, in the area of the Lusi vent a broad-band frequency range is related to the Lusi conduit. In this paper, we show that detailed microtremor surveys could be used as a preliminary and fast approach to locate mud conduits with sufficient precision.

Insights on the structure of Lusi mud edifice from land gravity data

Since May 2006, the active Lusi mud eruption has continuously erupted boiling mud. During the early stages of the eruption in 2006, previous gravity studies showed that the piling up of the mud constructed a large edifice that subsides within the unconsolidated sediment especially around a large area over the active crater. After ten years of continuous eruption, the size of the edifice has grown significantly over a surface framed by 10 m tall containment embankments. In 2015 and 2016, several land gravity surveys were carried out to investigate the structure of the mud edifice and the effect of local geological active features. The new residual Bouguer anomaly map, calculated for a reference density of 2670 kg m−3, shows significant changes in the local gravity field in comparison to the previous 2006-gravity map survey. The new data set shows that the gravity decrease is generally restricted along the faulted and fractured zones, around erupting vents, and in the southern part of the mud edifice. Maximum gravity variations reach 1.4 mGal in some areas of the mud edifice. In the region outside the embankment, the gravity reductions are 0.6 mGal E-W and 1.0 mGal N-S. A second vertical derivative analysis of gravity data indicates that the mud edifice continues to pile up and subside mostly in the western and southern part of the edifice. Results of a 3D forward model of a vertical cylinder shape allowed characterising the extent of compacted material along the Watukosek fault system that originates from the neighbouring volcanic arc and crosses the mud edifice. Our results support the hypothesis of local pinched volume of mud ongoing between the subsided and uplifted masses of mud. The density of compacted mud breccia material increases between 16 and 27%. Gravity data also shows that the Lusi mud edifice is built over an extended NW-SE gravity increase, interpreted as a sediment density variation within the basin, and which is parallel to the trend of the Basin.

Understanding the trigger for the LUSI mud volcano eruption from ground deformation signatures

Abstract The LUSI mud volcano in the sub-district of Porong, Sidoarjo, East Java, Indonesia started to erupt on 29 May 2006. An almost continuous eruption of a mixture of mud, water and gas has occurred around this area since this date. The eruption triggered vertical and horizontal ground deformation. From June 2006 to December 2010, 14 global positioning system campaigns were conducted to observe the ground deformation using c. 50 stations sparsely located up to 10 km from the eruption centre. Field observations of cracks, terrestrial laser scanning and geo-electrical measurements have also been used to infer the ground deformation signature around the LUSI mud volcano. More than 150 pairs of interferograms generated from 66 ALOS PALSAR images from June 2006 to December 2009 have also been used to study the ground deformation caused by the LUSI mud volcano. The LUSI mud eruption began only 200 m from where the Lapindo Inc. oil company was drilling for oil and gas. The drilling may have pierced a deeper high-pressure zone, causing an underground blow-out of the drillhole into a hydrofracture. Alternatively, the magnitude 6.3 Yogyakarta earthquake, which was located c. 275 km from the eruption site and occurred two days before the LUSI eruption, may have shaken the area sufficiently to cause the eruption by reactivating a fault in the region and liquefying the mud. These two hypotheses for triggering the mud volcano have been argued vehemently and still remain controversial. The ground deformation signatures provide important clues to understanding the trigger for the eruption and to solve this controversy. Co-seismic fault reactivation has its own typical ground deformation signature. This study used global positioning system and InSAR techniques, as well as field observations of cracks, terrestrial laser scanning and geo-electrical measurements, to determine the signature of ground deformation around the LUSI mud volcano and to explain the triggering mechanism.

A Quick Assessment Method for the Mud Eruption Hazard Risks of the Lusi Surrounding Area with a Special Reference to Ground Deformation Behavior

The Lusi mud eruption in Sidoarjo of East Java has provided huge impact to the people living in the surrounding area. The eruption has been followed by ground subsidence that has changed the ground structure. An assessment method has been introduced for analyzing the hazard. The method employs a rating system to quantify the hazard parameters, in which ground deformation parameters are significant. A hazard risk index is therefore obtained by multiplying hazard potential and vulnerability parameters.

Performances of Artificial Lightweight Geopolymer Aggregate (ALGA) in OPC Concrete

The non-availability of natural lightweight aggregate and demand are increasing in worldwide, thus new alternatives on producing artificial aggregate should be developed. This paper discussed on the mechanical properties of artificial lightweight geopolymer aggregate (ALGA) made from LUSI mud and alkaline activator in concrete. LUSI means Sidoarjo mud from Indonesia which erupted on 2006 with high volume and impacted an area of almost 770 hectare. The alkaline activator used was combination of sodium hydroxide and sodium silicate. The geopolymer paste formed need to be pelleted and sintered at 950 °C. The results showed that the compressive strength of OPC-ALGA concrete is 41.89 MPa at 28 days of testing with a density of 1760.1 kg/m3 which can be classified as lightweight concrete. The water absorption of ALGA concrete is 2.77%.

COMPARISON OF CONSOLIDATION CURVES FOR REMOLDED MUD VOLCANO OF SIDOARJO, INDONESIA

Sidoarjo mud volcano (Lusi) is one of the most challenging problems regarding to the compressibility of fine grained soils in Indonesia. Understanding about compressibility behavior is essential to construct appropriate remediation program for this problems. Consolidation test has been conducted to investigate the compressibility behavior of Lusi mud volcano. In this study, the laboratory test result is compared with estimated value derived from several empirical equations. A simple equation can be used to predict e-log σ’ curve very well by using the correlation between initial void ratio (e0) and void ratio corresponding to unit pressure (e1); and correlation between compression index (Cc) and physical properties of soils, such as liquid limit (wL) or natural water content (wn). This equation predict better than other available equations in literature when compared with laboratory test of Lusi mud volcano.

Influence of seismicity on the Lusi mud eruption

AbstractEarthquakes trigger the eruption of mud and magmatic volcanoes and influence ongoing eruptive activity. One mechanism that could trigger an eruption is clay liquefaction. Here we model the propagation of seismic waves beneath the Lusi mud eruption (East Java, Indonesia) using available seismic velocity and density models to assess the effect of subsurface structure on the amplification of incident seismic waves. We find that using an updated subsurface density and velocity structure, there is no significant amplification of incident seismic energy in the Upper Kalibeng Formation, the source of the erupting solids. Hence, the hypothesis that the Lusi eruption was triggered by clay liquefaction appears unlikely to be correct. Independent constraints from gas chemistry as well as analyses of drilling activities at the nearby Banjar‐Panji 1 gas exploration well and an analysis of the effects of other earthquakes all favor a drilling trigger.

Deep and shallow sources for the Lusi mud eruption revealed by surface deformation

AbstractThe Lusi mud eruption, in East Java, Indonesia, began in May 2006 and continues to the present. Previous analyses of surface deformation data suggested an exponential decay of the pressure in the mud source but did not constrain the location, geometry, and evolution of the possible source(s) of the erupting mud and fluids. To map the surface deformation, we employ multitemporal interferometric synthetic aperture radar and analyze a well‐populated L‐band data set acquired by the Advanced Land Observing Satellite (ALOS) between May 2006 and April 2011. We then apply a time‐dependent inverse modeling scheme. Volume changes occur in two regions beneath Lusi, at 0.3–2.0 km and 3.5–4.75 km depth. The cumulative volume change within the shallow source is ~2–3 times larger than that of the deep source. The observation and model suggest that a shallow source plays a key role by supplying the erupting mud, but that additional fluids do ascend from depths >4 km on eruptive timescales.

Seepage Monitoring of an Embankment Dam Using Resistivity Method: A Case Study of LUSI Mud Volcano P.79 - P.82 Embankment

Since the Lusi Mud volcano erupts in Sidoarjo, East Java, on May 2006, soil embankments have been built to keep hot mud within the ponds. Unfortunately, since the embankments were sitting on a poorly weak ground, land subsidence intensively occurred around the embankments. These subsidences are mainly caused by water seepage penetrating the embankment. To observe the part of the embankment that is vulnerable to water seepage, DC Resistivity method, being a non-destructive and versatile method, is used to monitor the subsurface condition of the embankment. P.79 - P.82 embankment, which has collapsed on December 2010 is highlighted in this study because it has the lowest height of all part the embankment, directly adjacent with water from the mud volcano in the inside and field crop on the outside. The research will show the fluctuating results of the water seepage in the embankment during the timeline of February 2012 - October 2013 which, unlike the result of another area, is highly affected by the water level at each measurement. The embankment height during each DC Resistivity measurement is also measured to compare the subsurface result with the condition on the surface. The resistivity subsurface cross section shows increasing water seepage in each measurement (February 2012, July 2012 and October 2013). Alarming seepage level displayed in December 2012 which is presumably triggered by the increase of water level during rainy season is also followed by cracks occurred in the surface.

The Growth of Mangroves in Created Wetland in the Porong River, East Java, Indonesia

Mangrove plantation projects have been established in the created mangrove wetland in the mouth of the Porong River, East Java, in parallel with the construction of reclamation area for LUSI mud dumping area. This study was aimed to assess the growth of planted mangrove in a created mangrove wetland in relation to the environmental parameters, which are sediment salinity, sediment fraction, pore water salinity, pH/eH, and total organic matter (TOM) in the sediment. Periodical measurement of mangrove growth Avicennia sp. and the environmental parameters were undertaken in the created wetland and in the mud flats of intact mangrove forest nearby the created wetland as the natural reference in July to November 2012. We found that sediments in the created wetland had different characteristics of sediment fractions, sediment salinity and TOM compared to sediments in the mud flats of intact forests. Sand dominated sediments with low TOM and higher water salinity in the created wetland as compared to those in the mud flats affected growth rate of mangroves in study sites. We suggest that TOM and salinity are important factors that contribute to the growth of mangroves in the Porong River. Keywords: Mangrove, salinity, Porong River, total organic matter.

Initial pore pressures under the Lusi mud volcano, Indonesia

The Lusi mud volcano of East Java, Indonesia, remains one of the most unusual geologic disasters of modern times. Since its sudden birth in 2006, Lusi has erupted continuously, expelling more than 90 million cubic meters of mud that has displaced approximately 40,000 people. This study undertakes the first detailed analysis of the pore pressures immediately prior to the Lusi mud volcano eruption by compiling data from the adjacent (150 m away) Banjar Panji-1 wellbore and undertaking pore pressure prediction from carefully compiled petrophysical data. Wellbore fluid influxes indicate that sequences under Lusi are overpressured from only 350 m depth and follow an approximately lithostat-parallel pore pressure increase through Pleistocene clastic sequences (to 1870 m depth) with pore pressure gradients up to [Formula: see text]. Most unusually, fluid influxes, a major kick, connection gases, elevated background gases, and offset well data confirm that high-magnitude overpressures also exist in the Plio-Pleistocene volcanic sequences (1870 to approximately 2833 m depth) and Miocene (Tuban Formation) carbonates, with pore pressure gradients of [Formula: see text]. The varying geology under the Lusi mud volcano poses a number of challenges for determining overpressure origin and undertaking pore pressure prediction. Overpressures in the fine-grained and rapidly deposited Pleistocene clastics have a petrophysical signature typical of disequilibrium compaction and can be reliably predicted from sonic, resistivity, and drilling exponent data. However, it is difficult to establish the overpressure origin in the low-porosity volcanic sequences and Miocene carbonates. Similarly, the volcanics do not have any clear porosity anomaly, and thus pore pressures in these sequences are greatly underestimated by standard prediction methods. The analysis of preeruption pore pressures underneath the Lusi mud volcano is important for understanding the mechanics, triggering, and longevity of the eruption, as well as providing a valuable example of the unknowns and challenges associated with overpressures in nonclastic rocks.

An extensive mud spill from the LUSI mud volcano -Review-

An extensive mud spill from the LUSI mud volcano -Review-

Physical Properties and Mineral Content of Sidoarjo Mud Volcano

Laboratory tests were conducted to assess the physical properties and mineral content of Sidoarjo mud volcano (or known as Lusi). These information are used to estimate the compression index which is considered to be important to support the reclamation program of the impoundment area. Physical properties of Lusi such as particle size distribution, Atterberg limits and specific gravity were determined in laboratory. Mineral content was observed through XRD test. Based on the Atterberg limit, the compression index was determined. The mineral content observed from the test are Chlorite and Illite. The results show that Lusi material consist of mostly fine-grained soil about 84.47% which dominated by clay size particle about 54.47% of total dry weight. Based on USCS it is classified as high plasticity silt (MH). New correlation has been proposed to estimate compression index from liquid limit and plasticity index using available data in literature. This new approach uses A-line in plasticity chart as boundary to database for developing the equations. Based on this separation of databases, more precise equations are obtained indicated by higher R value. Compression index of Lusi mud volcano is 0.367 from liquid limit-based calculation and is 0.454 from plasticity index-based calculation.

Characteristics of Lusi mud volcano and its impacts on the Porong River

Since the first gas and mud volcano spewed from well at Sidoarjo, East Java, Indonesia (called Lusi or Lapindo mud) in 2006, its keep flowing ever since. Despite the occurrence of Lusi mud volcano was debated. Either it was natural or unnatural disaster, but maintaining the impact of the mud on social and environment is important. In addition, monitoring water, land and air quality under permitable condition is urgently necessary, due to some scientist stated that the eruption of mud volcano might be impossible to stop. The Lusi’s mud was analyzed in 2009 and showed that the concentration of heavy metals were below environmental soil quality guidelines. There were no environmental effect of heavy metals (Mn, Zn, Cu, Cr, Cd, Pb, Co, Ni, Hg, and As) resulted of mud, unless when these metals are associated with other elements. In contrast, the physical and chemical of mud-water was above the environmental standard. Continues monitoring on mud and mud-water was required to protect the environment, thus human health.

Composition and flux of explosive gas release at LUSI mud volcano (East Java, Indonesia)

AbstractThe LUSI mud volcano has been erupting since May 2006 in the densely populated Sidoarjo regency (East Java, Indonesia), forcing the evacuation of 40,000 people and destroying industry, farmland, and over 10,000 homes. Mud extrusion rates of 180,000 m3 d−1 were measured in the first few months of the eruption, decreasing to a loosely documented <20,000 m3 d−1 in 2012. The last few years of activity have been characterized by periodic short‐lived eruptive bursts. In May and October 2011, we documented this activity using high‐resolution time‐lapse photography, open‐path FTIR, and thermal infrared imagery. Gases (98% water vapor, 1.5% carbon dioxide, 0.5% methane) were periodically released by the bursting of bubbles approximately 3 m in diameter which triggered mud fountains to ∼10 m and gas plumes to hundreds of meters above the vent. During periods of quiescence (1–3 min), no appreciable gas seepage occurred. We estimate that LUSI releases approximately 2300 t yr−1 of methane, 30,000 t yr−1 of CO2, and 800,000 t yr−1 of water vapor. Gas bubble nucleation depths are >4000 m for methane and approximately 600 m for carbon dioxide; however, the mass fractions of these gases are insufficient to explain the observed dynamics. Rather, the primary driver of the cyclic bubble‐bursting activity is decompressional boiling of water, which initiates a few tens of meters below the surface, setting up slug flow in the upper conduit. Our measured gas flux and conceptual model lead to a corresponding upper‐bound estimate for the mud‐water mass flux of 105 m3 d−1.

Triggered mud eruption?

The Indonesian government ruled that the Lusi mud eruption was triggered by drilling and held an oil company responsible. Instead, a curved rock layer capping the mud reservoir may have amplified passing seismic waves and the trigger may have been natural.

Lusi mud eruption triggered by geometric focusing of seismic waves

The Lusi mud eruption in Indonesia has been ongoing since 2006. Numerical simulations show that a parabolic-shaped layer in the rock surrounding the site of the Lusi eruption could have amplified and focussed incoming seismic energy from an earthquake, which then triggered the mud eruption.