Lombok Earthquake Research Articles

Post-earthquake quality of life among students

Quality of life is one of the many psychological impacts of post-disaster. One of the impacts of the North Lombok earthquake in 2018 was that many school buildings and residences were damaged and collapsed. This research aimed to determine the quality of life of boarders and public students displaced after the earthquake in North Lombok. This research was comparative research with cross-sectional design. The samples of this research were 85 students consist of 40 students of emergency public school and 45 students of emergency Islamic boarding school. This research variable was the quality of life of boarders and public students. Measurement of this study using KIDSCREEN-27 and analyzed by bivariate and multivariate analysis with the value of α<0.05. This study showed the quality of life for boarders students higher than public students (p=0.008).

Hypocenter and Magnitude Analysis of Aftershocks of the 2018 Lombok, Indonesia, Earthquakes Using Local Seismographic Networks

Abstract The island of Lombok in Indonesia is located between the Indo-Australian and Eurasian subduction trenches and the Flores back-arc thrust, making it vulnerable to earthquakes. On 29 July 2018, a significant earthquake Mw 6.4 shook this region and was followed by series of major earthquakes (Mw>5.8) on 5, 9, and 19 August, which led to severe damage in the northern Lombok area. In this study, we attempt to reveal the possible cause of the sequences of the 2018 Lombok earthquakes based on aftershock monitoring data. Twenty stations were deployed to record earthquake waveform data from 4 August to 9 September 2018. In total, 3259 events were identified using 28,728 P- and 20,713 S-wave arrival times during the monitoring. The aftershock hypocenters were determined using a nonlinear approach and relocated using double-difference method. The moment magnitude (Mw) of each event was determined by fitting the displacement spectrum amplitude using a Brune-type model. The magnitudes of the aftershocks range from Mw 1.7 to 6.7. The seismicity pattern reveals three clusters located in the Flores oceanic crust, which fit well with the occurrences of the four events with Mw>6. We interpret these events as the main rupture area of the 2018 Lombok earthquake sequence. Furthermore, an aseismic zone in the vicinity of Rinjani extending toward the northwestern part of Lombok was observed. We propose that the crust in this area has elevated temperatures and is highly fractured thus inhibiting the generation of large earthquakes. The aseismic nature is therefore an artifact of the detection threshold of our network (Mw 4.6).

Medical Emergency and Public Health Response in Disaster Settings: A Case Series of Pidie Jaya, Lombok and Palu Earthquakes

Indonesia is one of the most disaster-prone countries, often regarded as a “world disaster laboratory.” Natural disasters cause destruction and human suffering, especially in low- and middle-income countries Objective: This paper presents the overview of a medical emergency and public health response towards several recent earthquakes in Pidie Jaya, Lombok, and Palu of Indonesia. Case Series: The authors examine the appropriateness and effectiveness of the organized disaster response of the Pidie Jaya, Lombok, and Palu earthquakes in medical emergency response. Pidie Jaya Earthquake: A 6.4 magnitude earthquake struck off Pidie Jaya Regency, province of Aceh in Sumatra Island, Indonesia, resulting in 104 people died and others 395 injured. Lombok Earthquake: A series of moderate and strong earthquakes have rocked cities and regencies in Lombok Island, West Nusa Tenggara (NTB) causing 436 people died, 783 people with severe injury and 570 people with a mild injury. Palu Earthquake: The 7.7 magnitude earthquake hit Donggala district and also affected Palu city and Parigi Mountong regency causing 2657 people died, 4471 people with severe injury and 87,835 people with a mild injury. Important Findings: Though Indonesia has made outstanding progress in disaster management, the country still has many challenges and problems to overcome. The integration of data and information about health needs the progress of relief work, and about various other problems related to health is one of the most urgent and vital for better improving the medical emergency response and public health-related support in disaster settings.

Cascading Partial Rupture of the Flores Thrust during the 2018 Lombok Earthquake Sequence, Indonesia

AbstractA series of four Mw>6 earthquakes struck the northern region of Lombok, eastern Indonesia, in a span of three weeks from late July to mid-August 2018. The series was thought to be associated with the Flores thrust, but the exact mechanism causing the unusual earthquake series has remained elusive. Our Interferometric Synthetic Aperture Radar analysis, combined with insights from seismology, indicates that the events originated at different hypocenter depths with differing fault geometries, which may explain the cascading behavior of the events, and indicates that better imaging of active fault geometry might provide some insight into future rupture behavior on other similar thrust systems. Our static stress change calculations suggest that the earlier events in the sequence played a role in promoting the later events. In addition, the second event brought the most significant impact on a nearby volcano, by causing volumetric expansion at its shallow magma plumbing system and unclamping its magma ascent zone, which may potentially have an impact on its future eruptive activity. However, no volcanic activity has so far occurred after the earthquakes. Finally, our damage proxy maps suggest that the second event caused the greatest damage to buildings.

Analysis of Lombok 2018 earthquake effects on surface deformation process based on time lapse microgravity data (case study: east Lombok and central Lombok regencies)

Fault activities was detected during periods of 2016 to 2018 which presented by land subsidence in East Lombok and Central Lombok regencies during this period. In order to find out the impact of the earthquake which occurred from July to August 2018, time lapse microgravity anomaly before and after earthquake was compared, i.e. time lapse microgravity anomaly 2016 to 2018 period and 2018 to 2019 period. Measurements were carried out at about 80 points which distributed in both of regencies. Time lapse microgravity anomalies periods of 2016 and 2018 show positive values at all measurement points and deformation analysis revealed that subsidence occurred at all study areas. The results of the time lapse microgravity anomaly data processing between the periods of 2018 to 2019 show the opposite one. The results of data analysis and processing of time lapse microgravity anomaly during period 2016 to 2019 shows the deformation process on the surface before the earthquake Lombok and it was stopped due to the events of the Lombok Earthquake in 2018. The earthquake that generated by the thrust fault mechanism causing elevation change of the research area in Central Lombok Regency and East Lombok, an event of uplifting occurred.

RISBARI: an alternative house model for the 2018 Lombok earthquake affected people

Right after the 2018 Lombok earthquake, a huge number of housings were considered to be rebuilt or partially repaired. Out of more than 216,519 damaged houses, around 75,138 houses have to be demolished and rebuilt at the same location. This construction process is required to carry out immediately as majority of affected dwellers are now living at temporary shelters with very limited privacy. A house model made from cold formed steel structure, RISBARI, was proposed. RISBARI was developed to meet two essential criteria: fast erection process and construction budget constraints. A full scale test of RISBARI was conducted to evaluate its lateral strength capacity. This paper summarize the earthquake-resistant RISBARI house as well as the planning of its implementation in massive production through 5Ms principles.

Identification of Fault Structure in Lombok region, West Nusa Tenggara using Tomography Lombok Earthquake Data of July-August 2018

Lombok and Nusa Tenggara are one of the regions in Indonesia that have quite complex tectonic arrangements. With this order, not infrequently in the region there are often natural disaster phenomena. One of the most striking things is the occurrence of a series of earthquakes of magnitude Mw > 5.0 that rocked the northern region of the Island of Lombok on 29 July 2018 (Mw = 6.4), 5 August 2018 (Mw = 6.9), 9 August 2018 (Mw = 5.9), 19 August 2018 (Mw = 6.3 and 6.9) and 25 August 2018 (Mw = 5.5). This study aims to identify the condition of tectonic structures under the surface of the earthquake occurring region using the tomography method. This method utilizes earthquake travel time data recorded at 15 BMKG seismic stations. The tomogram results show the contrast of anomalous values in the Vp and Vs models. The contrast of the anomalous is associated with the presence of fault structures that have an allowance angle of about ± 20-30° and a thrust fault type, verified by focal mechanism ball data. This thrust fault is then indicated as the cause of the occurrence of earthquakes with magnitude Mw > 5.0, which shook the northern part of the island of Lombok in July-August 2018. According to the tomography result, the fault is located closer to the north side of Lombok Island than Flores Back arc Thrust.

Focal validation mechanism for Lombok earthquake with image analysis of satellite radar and crust movement GPS observation

Lombok Earthquake on August 5 and August 19, 2018, traces of deformation were analyzed with satellite image data to determine vertical deformation in the form of uplift on the ground surface. Earthquake wave analysis provides data on the mechanism at the epicenter in the form of a fault, the major forces axis in the form of the P axis, as well as the T axis, in addition to location and strength. The results of the focal analysis showed that the Lombok earthquake was an earthquake on the rising fault, the results of satellite radar image analysis showed the corresponding results, where the maximum increase occurred on the lip of the fault block in the form of a hanging wall. The direction of the acting force is indicated by the Axis P, in accordance with the research results of the Lombok earth crust movement, namely the N-NE Direction.

The Lived Experiences of the Lombok Earthquake Survivors

Background: The large-scale earthquake which had struck off Lombok, an island in West Nusa Tenggara, made the survivors faced poor conditions, difficulties, and lack of supplies. Besides physical losses, the survivors also experienced various psychological health disorders that significantly affected their psychological condition as well as life.Purpose: This study was aimed at exploring and gaining deeper meaning from the lived experiences of the Lombok earthquake survivors.Methods: This study used a qualitative method with a descriptive phenomenological approach to elucidate the phenomena from experiences. The participants were ten (10) survivors of the Lombok earthquake, who were determined by purposive sampling. Data were collected through in-depth interviews and analyzed using Colaizzi's method.Results: The results showed six emerging themes, including (1) problems solving skills when disaster strikes, (2) surviving from the limitations and difficulties, (3) feeling accustomed to earthquake, (4) family is a key source of strength to continue life, (5) getting closer to God by doing religious prayers and actions to have peace of mind, and (6) learning from the disasters to become a better human being.Conclusion: The lived experience of the Lombok earthquake survivors was a long journey where they survived and adapted the difficult situations, as later, they could turn the under-pressure conditions to chances for their personal development. The findings of this study provide insights for nurses to greatly contribute to solving post-disaster psychological issues by strengthening the survivors’ religious aspects, trauma healing, play therapy, and peer-support group.

Teaching Model for Disaster Preparedness School Based Earthquake Prone Earthquake in Lombok

The problem in this research is that the teaching of school-based earthquake disaster preparedness in Lombok has not been optimal. In fact, the island of Lombok is an area with a high level of vulnerability to earthquakes. This is because one of them is the Flores Thrust which stretches from the eastern tip of the Flores Sea to the north of Bali. Thus in this study the main objective is to develop a preparedness teaching model for earthquake-prone schools. Where earthquake disaster preparedness is all efforts and activities carried out before a natural disaster occurs, during a disaster and immediately after a disaster to quickly and effectively respond to the situation or situation. The research method used is a research and development approach (Research & Development). The results showed several results including; First, the use of this preparedness teaching model shows that schools have more knowledge as a result of modeling in learning; Second, the exposure of the functions and responsibilities of one of the main leading sectors in disaster management; and The three resulting teaching models have simplified disaster management in schools because they are integrated with Social Science learning so that they are easily realized. So with the model of teaching student preparedness it will be more effective and efficient in order to improve their ability to face earthquakes that can occur at any time.

The Resilience and Agricultural Household Livelihood Strategies of the 2018 Lombok Earthquake Victims at the Emergency Period in North Lombok Regency

A great earthquake was hitting Lombok in August 2018 that caused damage to home and livelihood sources of almost 100% of North Lombok Regency (KLU) population. This research is aimed to investigate the resilience capacity and livelihood strategies of displaced people (the earthquake victims) of KLU, especially the agricultural families during the post disaster emergency period. This research is using mix method between qualitative and quantitative approaches that explained descriptively. The qualitative data in this research was obtained using purposive area snowball sampling technique while the quantitative data was obtained through a comprehensive survey using Displacement Tracking Matrix (DTM) technique. Result of the research revealed that the earthquake caused the lost of jobs and livelihood sources of KLU’s people in all economic sectors, including agricultural sector. Social capital of the society was influencial as a main strategy of the victims to fulfil their daily needs and strengthen their social resilience in facing the damaging impact of the disaster. By exploiting their social capital, the society was able to fulfil their daily needs by managing all external aids, natural resources, and their remaining personal assets based on their common understanding, local wisdom, and social norms that exist in the society.

Did the Flores backarc thrust rupture offshore during the 2018 Lombok earthquake sequence in Indonesia?

SUMMARYThe Flores thrust forms the west segment (∼450 km) of a very active, ∼E–W striking, ∼800-km-long backarc thrust along the east Sunda Arc. In 2018, a deadly earthquake sequence composed of ~110 M4+ events rattled the Indonesian island of Lombok near the Flores thrust and caused tremendous damage on the island, however what is the nature of rupturing during this earthquake sequence remains unknown. Here, using a total of 2120 km of high-resolution seismic profiles covering ∼300 km of the Flores thrust off Bali, Lombok and Sumbawa, in addition to earthquake data and InSAR measurements, we investigated the active thrusting during this earthquake sequence. Our seismic interpretation and structural mapping show that offshore north of Lombok and Bali, the remarkable Flores thrust is essentially blind, deforming the seabed by folds, not faults. The Lombok earthquakes were all shallow thrust events with depth <40 km and occurred within ∼35 km north of the Rinjani volcano beneath the Lombok Island and its northern extremity. The InSAR measurements suggested that the most of the crustal deformation caused by these earthquakes occurred the north the and northeast of the island. The maximum vertical deformation was ∼36 cm near the northwest margin of the island, caused by the 5th August Mw 6.9 event. These observations combined with the presence of blind thrusts off Lombok suggest that the offshore portion of Flores thrust did not rupture during the 2018 Lombok earthquake sequence; the most coseismic slip must have occurred along a deep-rooted, north-verging basal fault and a range of imbricate thrusts beneath the north of the island, not along the buried thrusts offshore. Despite being blind off Lombok and Bali, the Flores thrust can still pose tsunami threats to the adjacent population centres by rupturing the seafloor during future large earthquakes (M > 7) that occur directly on the offshore blind thrusts, not beneath the island like the Lombok sequence. The proximity of the Rinjani volcano and thrust earthquakes suggests a possible role of volcanic activity (e.g. magmatic fluids and gas migration, stress change induced by pressurized magma chamber) in inducing the Lombok earthquakes.

Characteristics of the Seismogenic Faults in the 2018 Lombok, Indonesia, Earthquake Sequence as Revealed by Inversion of InSAR Measurements

AbstractWe invert Interferometric Synthetic Aperture Radar observations for the slip models of the 28 July Mw 6.4, 5 August Mw 6.9, and 19 August Mw 6.9 earthquakes in the 2018 Lombok earthquake sequence. The geodetic measurements and aftershock distribution suggest three south-dipping fault planes with shallow depths for the three events. They are likely associated with the imbricate thrust faults above the main Flores fault. Obvious strike and dip differences were found on the seismogenic faults, which implies probable fault segmentation and explains the cascading fault behaviors with moderate magnitudes. The three events peaked at depths of 12.38, 16.9, and 25.9 km. The estimated moments reach 7.59×1018, 3.33×1019, and 4.61×1019 N·m, equal to Mw 6.52, Mw 6.95, and Mw 7.04 events, respectively. The derived slip distribution covers most of the area in the Lombok fault plane. Future seismic hazard on the seismic gap to the east of Lombok should be noted.

Analysis of school damage due to Lombok earthquake on August 2018

The Lombok earthquakes on 5 and 19 August, 2018 have caused fatality and damage buildings including houses and schools. It was reported that the Lombok earthquake had caused damage to at least 606 schools in West Nusa Tenggara. Following the earthquake, the field survey was carried out in a few days to collecting data of damaged schools in Lombok. The global positions of surveyed schools were recorded during the survey to identify the geological and seismicity condition surrounding area. The data were analyzed to understand the cause of the damaged. The damage pattern of the schools is also analyzed and then compared to the other related studies. The damage on the schools in Lombok Island generally has a result of insufficient quality of the building materials. Further, understanding the earthquake resistant building for earthquake prone areas is the most basic knowledge to be informed to the Local Government who has authority to manage the schools. This study suggests for establish Local formal rule of related to minimal requirement for earthquake resistant school building following the microzonation.

Risk analysis of seismic bridge damage: case study after Lombok and Palu earthquake

Indonesia is known as an earthquake-prone region, lies in the ring of fire zone. This potential hazard can impact several infrastructures, including bridges. Seismic bridge damages could possibly disrupt traffic flow furthermore cut off the regional connectivity. In this study, risk analysis is carried out on several bridges after Lombok and Palu earthquake. Visual inspection has been undertaken on 38 bridges on-site, and several damages identification are reported. Risk analysis was then carried out according to the severity of element damages and the frequency of occurrence. From the analysis, it is concluded that embankment settlement in the approach road is found to be the most potential element with the highest risk of damage due to earthquakes. Besides, the superstructure displacement and crack in the wing wall are at moderate risk. This finding makes the substructure become the most vulnerable element which needs more attention. Therefore, it is recommended to specify a higher design specification for substructure to mitigate seismic bridge damages, especially for bridges located in the high seismic zone area.

Management of Tourism Areas Based on Disaster Mitigation (Case Study of Senggigi Beach)

Tourism is often associated with magnificence and pleasure. But behind that, tourism is a very vulnerable and fragile economic activity. One of the vulnerabilities that overshadow tourism is the occurrence of natural disasters. In Indonesia, several disasters have caused an impact on the tourism industry, such as the Lombok earthquake that took place in 2018 causing 4,636 tourists to be victims, 100,000 tourists reduced, and losses of 1.4 trillion in the tourism sector. The purpose of this study is to identify tourism area management based on disaster mitigation. This research was designed using qualitative methods. The data collection uses field observation techniques, documentation, and in-depth interviews. The determination of the island of Lombok as a research location is because this region has a variety of interesting natural tourism potentials, such as the Senggigi beach which is located on the west coast of Lombok Island. Senggigi areas have a high earthquake and tsunami vulnerability. Based on research, it is known that Senggigi Beach needs to get more attention in terms of disaster mitigation, such as the making and installation of disaster-prone maps, the addition of evacuation signs, evacuation route maps, shelters, beach belts or buildings as breakwaters, and also monitoring towers. This is useful to provide a sense of security and comfort for tourists visiting the tourist sites.

Lombok earthquake, one year later: housing sector recovery

The series of strong earthquakes that hit the province of West Nusa Tenggara (NTB) on 29 July 2018 (M6.4), 5 August 2018 (M7.0), 9 August 2018 (M6.2) and 19 August 2018 (M6.5 and M6.9) has caused many casualties, injuries as well as damages in the housing sector. The disaster emergency was stated on July 29th, 2018 and was extended several times up to August 25th, 2018. A transition period from an emergency situation to recovery was declared starting from August 26th, 2018 to February 26th, 2019, while the rehabilitation and reconstruction (R & R) phase was started from February 27th. , 2019. In the R & R program, the Government has established a policy of building earthquake-resistant houses with a self-managed system through the formation of community groups (POKMAS) consisting of house owners, supported by technical and administrative facilitators. There are many models of earthquake resistant houses, both those proposed by the government and the private sector that are approved by the government. A Presidential Instruction (Inpres) Number 5 Year 2018 was issued on 23 August 2018 to provide guidance on the housing sector reconstruction. An investigation to study and document the lessons learnt from the housing reconstruction process is conducted in Lombok Island, covering the issues of program management, institutional set up and coordination, project administration, technical design, quality assurance and community participation. It was found that there were so many house building models proposed to the community by various sponsors, which cause confusion to the affected community. The study also found that the house reconstruction program has been delayed during the process, as one year after the earthquake, there were only about 52 thousands houses which have been completed, and 80 thousands other are still in progress, compared to the total of more than 237 thousand affected houses to be repaired and rebuilt. The study is expected to reveal various impeding issues and propose solutions for expediting the process. It is also expected that the result of the study can be used as a reference for future post-disaster housing sector recovery program in other places.

Grouting performance of the Pandan Duri dam shacked by Lombok earthquake 2018

The Pandan Duri dam has an important role in water supply in the East Lombok District. Unfortunately, Lombok Island is located in a relatively high seismic risk area, as earthquakes occurred in 2018 have ruined almost one third of the island and destroyed thousands of buildings. The Pandan Duri dam is one of many infrastructures shacked by the earthquake. Modelling the dam shows that the grouting installation of the dam has supported the dam after the earthquake. The factor of safety (FoS) of the dam was still 1. 76 after the earthquake for the flood water level conditions; but, the displacements could be significant to the stability of the dam, as the dam might displace up to 1. 64 m. Although, the current grouting support system might provide the stability to the dam during earthquake events, the dam will certainly require further stability enhancement and close monitoring for possible similar events in the future.

Penentuan Asumsi Waktu Berakhirnya Gempa Susulan Studi Kasus Gempabumi Lombok 5 Agustus 2018

Indonesia is located at the meeting point of three active tectonic plates. The consequence is the country is very prone to earthquake disaster, one of the most devastated events is Lombok earthquake occurred on 5 August 2018. The aim of this study is to estimated ending time of aftershock using Omori, Mogi I, Mogi II, and Utsu method . Based on the result of Mogi I and Utsu method which has the correlation coefficient closest to -1 it is predicted that aftershock will stop on 96 th weeks after the mainshock. By calculating the time data obtained, it is predicted that the aftershock will stop on the first week of June 2020.

Deskripsi Jenis Tindakan Operasi Pasien Bencana Gempa Bumi Lombok di RSUD Provinsi NTB Tahun 2018

Background: After an earthquake occurs, local medical infrastructure often is damaged or destroyed. Planning, efficient allocation of resources, and an understanding of the types of injuries that might occur. Orthopedic surgeons an important role in providing care for earthquake victims. Long bone fractures, soft tissue injuries, limb injuries/fractures can survive with proper care. Therefore, after an earthquake it is very important to know what types of operations or actions are often needed in dealing with injuries after an earthquake, especially in the field of orthopedics.
 Method: This research is a retrospective descriptive study using medical records of patients affected by the Lombok earthquake. The sample size is determined by the consecutive sampling method. Samples were patients affected by the Lombok earthquake in 2018 who met the inclusion criteria in the Medical Record data at the Provincial General Hospital of West Nusa Tenggara in 2018.
 Result: In this study, there were 199 patients with a ratio of the number of men (49.2%) and women (50.8%). The most common types of operative actions were debridement 34.2%, ORIF 31.2%, craniotomy 13.1%, laparotomy 6.5%, debridement and ORIF 0.5%, WSD 2%, laminectomy 5%, skin graft and OREF respectively 1%, amputation, burrhole, and maxilla reconstruction were 0.5%. The highest classification of trauma is due to fracture 67.8%, head/intracranial trauma 14.7%, thoracic, abdominal/pelvic trauma 8.5%, crush injury and skin loss 1%, other trauma 7%.
 Conclusion: Variations in trauma injury and operative actions due to the Lombok earthquake require medical personnel, especially orthopedists, to properly handle trauma cases.