Seismogenic Anomalies in Atmospheric Gravity Waves as Observed from SABER/TIMED Satellite during Large Earthquakes

Atmospheric disturbances caused by seismic activity are a complex phenomenon. The Lithosphere–Atmosphere–Ionosphere Coupling (LAIC) (LAIC) mechanism gives a detailed idea to understand these processes to study the possible impacts of a forthcoming earthquake. The atmospheric gravity wave (AGW) is one of the most accurate parameters for explaining such LAIC process, where seismogenic disturbances can be explained in terms of atmospheric waves caused by temperature changes. The key goal of this work is to study the perturbation in the potential energy associated with stratospheric AGW prior to many large earthquakes. We select seven large earthquakes having Richter scale magnitudes greater than seven ( M > 7.0 ) in Japan (Tohoku and Kumamoto), Mexico (Chiapas), Nepal, and the Indian Ocean region, to study the intensification of AGW using the atmospheric temperature profile as recorded from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite. We observe a significant enhancement in the potential energy of the AGW ranging from 2 to 22 days prior to different earthquakes. We examine the conditions of geomagnetic disturbances, typhoons, and thunderstorms during our study and eliminate the possible contamination due to these events.

Association of major earthquakes (magnitude >= 6 Richter scale) with geomagnetic activity index KP during the period 2001-2007

A critical study of variation of geomagnetic activity index Kp for the period 2001-2007 have been made and its close association with major earthquakes (magnitude >= 6 Richter scale) is presented. From statistical analysis it is confirmed that when Kp touches 0 or 0+ values, major earthquakes take place within 48 hours. This is also explained considering the motion of the molten metal inside the outer core of earth.

Method for Tuning the Parameters of Active Force Reducing Building Vibrations—Numerical Tests

The paper formulates a method of active reduction of structure vibrations in the selected resonance zones of the tested object. The method ensures reduction of vibrations of the selected resonance zones by determining the parameters of the active force that meets the desired dynamic properties. The paper presents a method for determining the parameters of the active force by reducing the vibrations of the structure in its resonance zones to a given vibration amplitude. For this purpose, an analytical form was formulated, which will clearly define the dynamic properties of the tested object and the force reducing the vibrations in the form of a mathematical model. The formulated mathematical model is a modified object input function, which in its form takes into account the properties of the active force reducing the vibrations. In such a case, it is possible to use the methods of mechanical synthesis to decompose the modified characteristic function into the parameters of the system and the parameters of the force being sought. In the formulated method, the desired dynamic properties of the system and the vibration reducing force were defined in such a way that the determined parameters of the active force (velocity-dependent function) had an impact on all forms of natural vibrations of the tested system. Based on the formalized method, the force reducing the vibrations of the four-story frame to the desired displacement amplitude was determined. Two cases of determining the active force reducing the vibrations to the desired vibration amplitude of the system by modifying the dynamic characteristics describing the object together with the active force were considered. For both cases, the system’s responses to the oscillation generated by harmonic force of frequencies equal to the first two forms of natural vibrations of the tested system were determined. In order to verify the determined force reducing the vibrations of the object and to create a visualization of the analyzed phenomenon, the building structure dynamics were analyzed with the use of PLM Siemens NX 12 software. The determined force parameters were implemented into the numerical model, in which the tested system was modelled, and the response time waveforms were generated with regard to the considered story. The generated waveforms were compared with the waveforms obtained in the formalized mathematical model for determining the active force reducing the vibrations. The vibrations of the tested numerical model were induced by the kinematic excitation with the maximum amplitude equal to 100 mm, which corresponds to the vibration amplitude during the earthquake with a force equal to level 5 on the Richter scale.

Earthquake in Assam and North Bengal and COVID19 in India

Earthquake in Assam and north Bengal in IndiaOn April 28, 2021, a 6.4 Richter scale earthquake affected the Sonitpur district of Assam, the tremors of which were felt in north Bengal and other parts of North-East India, as reported by the National Centre for Seismology1. Six more tremors followed the first shake 2. There were reports of widespread damage to buildings and other structures from across Assam, mostly in the central and western towns of Tezpur, Nagaon, Guwahati, Mangaldoi, Dhekiajuli, and Morigaon3. Again on May 3rd, 2021, an earthquake was felt in the Sonitpur district of Assam with a 3.7 magnitude on the Richter scale4. Assam disaster management authority reported that 10 people from 4 districts suffered physical injuries since the first attack on April 28, 2021, and some more time will be needed to know about the actual amount of damage that had taken place5. According to the National Centre for Seismology, the area affected by the earthquake is seismically very active and falls in the highest seismic hazard zone where the Indian tectonic plate subducts with the Eurasian plate because of which there are high chances of future quakes as well6.

Evaluation of Building Vulnerability to Earthquake Using Rapid Visual Screening (RVS) Method

Indonesia is one of the countries prone to earthquakes. One of the earthquake disasters that occurred several years ago hit Palu and Donggala on September 28, 2018. It caused severe damage to infrastructure. Therefore, it is necessary to evaluate buildings vulnerable to earthquakes as a form of prevention. One of the buildings in Jember, the dr. Soebandi hospital, experienced cracks in the walls during an earthquake measuring 6.0 on the Richter scale in Nusa Dua Bali on July 16, 2019. This study carried out the risk assessment of the vulnerability of buildings to earthquakes using the Rapid Visual Screening (RVS) method from FEMA P-154. RVS is a method to identify a building that is potentially vulnerable to earthquake hazards based on visual observations from the exterior and interior of the building. The results of the evaluation using the RVS method showed that the dr. Soebandi hospital is categorized as safe and not prone to earthquakes, with a potential vulnerability percentage of 0.0126%. Based on these results, the building does not require special treatment to anticipate earthquakes; however, maintaining the occupants' safety and extending the building's life requires routine maintenance.

Analysis Using High-Precision Airborne LiDAR Data to Survey Potential Collapse Geological Hazards

On August 8, 2017, an earthquake of magnitude 7.0 on the Richter scale occurred in Jiuzhaigou, Sichuan, causing significant damage to both life and property. Traditional geological hazard investigation is difficult in Jiuzhaigou because of the high altitude, the high-altitude canyons, and the vegetation-covered seismic areas. This study explores the technical advantages of using airborne LiDAR technology to penetrate vegetation and gather information directly from the surface, rapidly acquiring airborne 3D point cloud data in difficult areas. Through the preprocessing of data, the high-precision digital terrain and landform results were obtained. Comparative research found that the DEM obtained by high-precision airborne LiDAR technology has significant advantages in terms of the accuracy, details, and microgeomorphology of the data collected. The results can be directly used in the early identification of disasters, such as during the initial collapse or for disaster management. Studies have shown that airborne LiDAR has the technical advantage of penetrating vegetation to the surface and can, therefore, be used to guide the early identification and management of geological disasters in similar areas in the future.

Implication between Geophysical Events and the Variation of Seasonal Signal Determined in GNSS Position Time Series

The seasonal signal determined by the Global Navigation Satellite System (GNSS), which is captured in the coordinate time series, exhibits annual and semi-annual periods. This signal is frequently modelled by two periodic signals with constant amplitude and phase-lag. The purpose of this study is to explore the implication of different types of geophysical events on the seasonal signal in three stages—in the time span that contains the geophysical events, before and after the geophysical event, but also the stationarity phenomena, which is analysed on approximately 200 reference stations from the EPN network since 1995. The novelty of the article is demonstrated by correlating three different types of geophysical events, such as earthquakes with a magnitude greater than 6° on the Richter scale, landslides, and volcanic activity, and analysing the variation in amplitude of the seasonal signal. The geophysical events situated within a radius of 30 km from the epicentre showed a higher seasonal value than when the timespan did not contain a geophysical event. The presence of flicker and random walk noise was computed using overlapping Hadamard variance (OHVAR) and the non-stationary behaviour of the time series of the CORS coordinates in the time frequency analysis was done using continuous wavelet transform (CWT).

Belajar dari KKN Kebencanaan: Pola Distribusian Bantuan Paska Gempa Lombok antara MDMC dan BPBD

Indonesia adalah salah satu negara yang memiliki berbagai macam potensi bencana seperti gempa bumi. Salah satu kejadian gempa bumi dengan kekuatan yang mencapai 6,8 Skala Richter (SR) terjadi di pulau Lombok Provinsi Nusa Tenggara Barat (NTB). Komponen penting yang sangat berperan dalam manajemen bencana adalah distribusi bantuan paska bencana. Program Pengabdian Masyarakat (PKM) dengan tema kebencanaan diinisiasi oleh Universitas Muhammadiyah Mataram. Sejumlah 30 mahasiswa dikirim untuk membantu program distribusi bantuan paska gempa di dua simpul pengelolaan bantuan yaitu Muhammadiyah Managament Disaster Center (MDMC) yang bertempat di Gedung Dakwah Pengurus Wilayah Muhammadiyah (PWM) NTB dan Badan Penanggulangan Bencana Daerah (BPBD) yang bertempat di kantor BPBD NTB. Dari kegiatan ini disimpulkan bahwa tata kelola dan strategi dalam pengelolaan distribusi bantuan bencana yang dilakukan oleh MDMC dan BPBD memiliki karakteristik yang berbeda, hal ini terkait dengan ‘payung’ operasional yang diacu oleh kedua lembaga tersebut. Beberapa karateristik perbendaan tersebut adalah sumber dana, sistim koordinasi, dan sumberdaya yang pada akhirnya menghasilkan perbedaan dalam alur distribusi.Kata Kunci: Bencana; BPBD; Distribusi Bantuan; MDMC; Paska Gempa Learning from Disaster Community Service: Distribution Pattern of Post-Lombok Earthquake Aid between MDMC and BPBDABSTRACTIndonesia is one the countries that has various potential disasters such as the Earth Quake. One of the Earth Quakes that reached magnitude of 6.8 Richter Scale (SR) was occurred at Lombok Island Province of West Nusa Tenggara (NTB). A critical component that plays in the disaster management is humanitarian logistic supply. The community services program (PKM) with disaster theme was initiated by Universitas Muhammadiyah Mataram. Total of 30 students were sent for assisting the humanitarian logistic supply post-earth quake at two main distribution focal point, namely Muhammadiyah Disaster Management Centre that located at Gedung Dakwah Pengurus Wilayah Muhammadiyah (PWM) NTB, and The Provincial Disaster Management Office (BPBD) that located at BPBD NTB office. The PKM concluded that the distribution of humanitarian logistic by MDMC and BPBD has different characteristic associated with management and strategy, these differences occurred due to operational guideline that referred by those two institution. Some of the characteristic differences include funding resource, coordination system, and human resources that generated the different distribution flow. Keywords: Disaster; BPBD; Distribution Aid; MDMC; Post Earth Quake

Impact of 8th October 2005 Earthquake Associated with Kashmir Boundary Thrust (KBT), Pakistan

An earthquake on Richter scale of 7.6 intensity, originated from part of a fault zone more than 200 km long between Balakot and Reasi region of Jammu. This fault joins Indus Kohistan Seismic Zone (IKSZ). The epicenter was 11 km North - Northeast of Muzaffarabad while the depth was 15 km. The rupture zone along Kashmir Boundary Thrust was about 70 km in length. The area of impact is predominantly high relief with steep slopes, V-shaped valleys, and gorges. As a consequence of this seismic activity, about 70,000 people died while three-quarters of a million people were displaced. Most Govt. buildings including schools collapsed. Framework structures, wooden buildings and some buildings of NGOs built to withstand strong earthquakes in the area generally survived with minor damage. Communication networks collapsed disrupting rescue operations. Unavailability of helicopters in sufficient numbers, the absence of disaster management organization, lack of experience in rescue operations, and absence of locally available heavy machinery like lifts, cranes, bulldozers made the rescue extremely difficult resulting in very heavy losses. The government of Pakistan allocated 5 billion dollars for rehabilitation. However, the major contributor to the rehabilitation effort was Saudi Arabia. Physical changes (drying up of springs, temporary damming of streams, and increase in erosion) and ecosystem services destruction resulted due to this earthquake. Balakot city site located on rupture zone was very poor but situation was excellent since it was and even now is a hub of trade plus tourism for both Northern areas (GB) as well as Azad Jammu and Kashmir.

Analisis Kapasitas Seismik Struktur Gedung Kantor Dinas KetahananPangan Provinsi Sumatra Barat

The office building of the food security office of West Sumatra Province is a multi-storey building with reinforced concrete structures built in earthquake-prone areas that have the potential for large-scale earthquakes such as the one that occurred in 2009. Based on USGS data, from December 2004 to October 2009 There have been 10 earthquakes measuring more than 5 on the Richter scale that rocked Indonesia and resulted in damage to buildings, both minor damage to heavy damage and evencollapsing. The big earthquake that occurred on September 30, 2009 in Padang City, West Sumatra, was measuring 7.6 on the Richter scale. In this study, evaluated the seismic capacity of a reinforced concrete building 4 (four) floors built in earthquake-prone areas in the city of Padang. The seismic capacity of the building is evaluated based on the standard published by Japan, namely The Standard for Seismic Evaluation of Existin Reinforced Concrete Building, 2001. In this evaluation, it only looks at the structural elements of the column on the first floor. Seismic capacity is expressed in terms of the lateral strength index and the ductility index of the building. The results of the evaluation of seismic capacity obtained the total strength index value of the building is 0.707. The seismic capacity of this building can be shown to be adequate or strongin earthquake-prone areas compared to the seismic capacity of reinforced concrete buildings that survived the massive earthquake of 7.6 on the Richter Scale in West Sumatra in September 2009. From the evaluation results on this building which is located in an area including the prone to strong earthquakes can be stated to be able to behave ductile and able to withstand an earthquake or not experience sudden collapse