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Multihazard Disaster Engineering during the Response Phase
Published in Syed Hyder Abbas Musavi, Early Warning-Based Multihazard and Disaster Management Systems, 2019
Earthquake early warning centres if established in the country, can predict an earthquake disaster minutes before it strikes the population. Research in earthquake engineering offers guidance that properly established earthquake early warning centres, through continuous monitoring of seismic station activities along the established historic fault lines, may give warning times on national channels of telecommunication. Not only this, but also the seismic activity sometimes generates ELF/VLF signals similar to one that caused severe earthquakes in the past, may be communicated to authorized centres for decision making of issuing early warning signals or not. This should be a monotonous process of research and, if continued for some period, may lead to “CONFIRMED” warning messages of even hours before an earthquake hits. However, we produce the scenario based upon the existing facilities the nation possesses and extract the communication needs of the future from that scenario. On October 8, 2005, at 8:50 local time, a 7.6 magnitude earthquake hit Muzaffarabad in Pakistan. Similar earthquakes with 7.6/7.7 magnitudes rocked San Francisco in 1906, Quetta in 1935 and Gujarat in 2001. The Government of Pakistan released information saying that the official death toll was 73,267, while officials say that around 1400 people died in India and that 4 people died in Afghanistan. The total death toll was over 74,500. The earthquake caused severe damage to lives, buildings and property, rendering homeless about 3.3 million people. The exact epicenter was about 11.8 miles northeast of Muzaffarabad and 65 miles northeast of Islamabad, the capital city of Pakistan. The hypocenter of the earthquake was located at a depth of 16.2 miles below the surface. The damage caused by the earthquake was devastating, the worst being in northern Pakistan, but also affecting other areas including Afghanistan, India and the southern parts of the Kashmir Valley. Islamabad and Karachi felt an aftershock of 4.6 on the Richter scale. There were 147 aftershocks on the first day after the initial shock. One of the highest aftershocks was recorded at 6.2. There were 28 aftershocks that had a higher magnitude. On October 19, 2005, a series of aftershocks were also felt, one with a magnitude of 5.8; this was located 40.5 miles above Muzaffarabad. There were more than 978 aftershocks recorded, all of which occurred daily and continued until October 27, 2005.
An efficient energy measurement system based on the TOF sensor for structural crack monitoring in architecture
Published in Journal of Information and Telecommunication, 2023
Tran Anh Khoa, Pham Duc Lam, Nguyen Hoang Nam
This article was presented an IoT monitoring system for structural health over the MQTT protocol. The advanced solution monitors the shape of a structure by estimating its dynamic response and tracking the development of modal parameters such as natural displacement. Failures in a structure have been found to correspond to changes in dynamic behaviour, with a resulting change in natural displacement. The proposed system includes a low-cost ToF sensor and an accelerometer used to measure the acceleration of the building on which it is located. These measurements are sent to a remote host via the MQTT protocol. A specially developed web application then allows each authorized user to evaluate the structure's health in real time by testing the dynamic response of the design. In addition, the user can display measured data along each sensor axis to retrieve historical data and send commands to the sensor. In the future, the system could use a NoSQL database or time-series database to evaluate or store more significant amounts of data, including non-data structures, from an increased number of devices. Considering the architectural module of the proposed solution, another data layer in the foundation block would not involve structural changes to the entire application. For this reason, the system was deployed and tested in central Vietnam. Given the performance of the proposed IoT solution, future studies will focus on its use in earthquake early warning systems.
Research on compressive sensing of strong earthquake signals for earthquake early warning
Published in Geomatics, Natural Hazards and Risk, 2021
Jiening Xia, Yuanxiang Li, Yuxiu Cheng, Juan Li, Shasha Tian
Earthquake early warning is an effective method for disaster reduction and prevention, which has developed rapidly in the world in recent years. Oriented to practical applications, this article focuses on the hot research question how to reduce the amount of data in the collection and transmission of strong earthquake signals without affecting the signal quality. The research is based on the theory of compressive sensing (CS), that is, if a signal is sparse in an orthogonal space, it can be compressed at a sampling rate much lower than the Nyquist sampling rate, and may be reconstructed with high probability. Especially it’s emphasized that the sparseness of the signal may be one of the essential conditions of compressive reconstruction. The combination of compressive sensing theory and earthquake early warning brings great convenience to the signal sampling, storage, transmission and processing. Besides, it’s the subversion of the traditional strong earthquake signal analysis method-replacing the traditional strong earthquake sampling value with the observation value in the compressive sensing theory, which will inevitably lead to a fundamental change in signal characteristics, and then affect the relevant theories and technique systems of strong earthquake signals. It is of great practical significance to apply compressive sensing in the field of earthquake early warning to explore new methods of strong earthquake signal processing. The various key technologies in compressive sensing of strong earthquake signals are the basis for its practical application.
A Prototype Earthquake Early Warning System for Northern India
Published in Journal of Earthquake Engineering, 2021
Bhanu Pratap Chamoli, Ashok Kumar, Da-Yi Chen, Ajay Gairola, Ravi S. Jakka, Bhavesh Pandey, Pankaj Kumar, Govind Rathore
In such a scenario, an earthquake early warning (EEW) system could prove to be a boon for short-term earthquake disaster mitigation. An EEW system is generally defined as a system which can process seismic activity in real time from a remote location, and issue warning prior to significant ground shaking to industries as well as to general public. This can be achieved by detecting the ground motion radiating from an earthquake rupture and estimating the resulting ground shaking that will occur later in time either at the same location or some remote location.