IoT-Fog-Cloud Centric Earthquake Monitoring and Prediction

Earthquakes are among the most inevitable natural catastrophes. The uncertainty about the severity of the earthquake has a profound effect on the burden of disaster and causes massive economic and societal losses. Although unpredictable, it can be expected to ameliorate damage and fatalities, such as monitoring and predicting earthquakes using the Internet of Things (IoT). With the resurgence of the IoT, an emerging innovative approach is to integrate IoT technology with Fog and Cloud Computing to augment the effectiveness and accuracy of earthquake monitoring and prediction. In this study, the integrated IoT-Fog-Cloud layered framework is proposed to predict earthquakes using seismic signal information. The proposed model is composed of three layers: (i) at sensor layer, seismic data are acquired, (ii) fog layer incorporates pre-processing, feature extraction using fast Walsh–Hadamard transform (FWHT), selection of relevant features by applying High Order Spectral Analysis (HOSA) to FWHT coefficients, and seismic event classification by K-means accompanied by real-time alert generation, (iii) at cloud layer, an artificial neural network (ANN) is employed to forecast the magnitude of an earthquake. For performance evaluation, K-means classification algorithm is collated with other well-known classification algorithms from the perspective of accuracy and execution duration. Implementation statistics indicate that with chosen HOS features, we have been able to attain high accuracy, precision, specificity, and sensitivity values of 93.30%, 96.65%, 90.54%, and 92.75%, respectively. In addition, the ANN provides an average correct magnitude prediction of 75%. The findings ensured that the proposed framework has the potency to classify seismic signals and predict earthquakes and could therefore further enhance the detection of seismic activities. Moreover, the generation of real-time alerts further amplifies the effectiveness of the proposed model and makes it more real-time compatible.

Inhomogeneous precursor characteristics of rock with prefabricated cracks before fracture and its implication for earthquake monitoring

Earthquake precursors and earthquake monitoring are always important in the earthquake research field, even if there is still debate about the existence of earthquake precursors. However, it is extremely difficult to observe the seismogenic environment of earthquakes directly. Laboratory rupture experiment is a useful technique to simulate and gain an insight into the complex mechanisms of earthquakes. Five marble samples with prefabricated cracks are used for uniaxial loading experiments to investigate whether there is a precursory signal before rock fracture and to simulate the rupture process of strike-slip fault. The existence of a precursory signal is confirmed by the coefficient of variation (CV) results, from which we can see two patterns which are known as seismicity acceleration and quiescence before an earthquake. Moreover, these CV findings are applied to determine the locations of large deformation sampling points on the rock surface at different loading stages. Similar results are obtained when we consider actual seismicity at the northern end of the San Andreas Fault in California, which provides crucial evidence to prove the existence of precursor characteristics. In this case, three kinds of seismic monitoring models are designed to find out how to monitor these characteristics more effectively.

The Contribution of Submarine Optical Fiber Telecom Cables to the Monitoring of Earthquakes and Tsunamis in the NE Atlantic

Recent developments in optical fiber cable technology allows the use of existing and future submarine telecommunication cables to provide seismic and sea-level information. In this work we study the impact of three different technologies, 1) SMART, Science Monitoring and Reliable Telecommunications; 2) DAS, Distributed Acoustic Sensing, and; 3) LI, Laser Interferometry, for effective earthquake and tsunami monitoring capabilities on the NE Atlantic. The SW Iberia is the source area of the largest destructive earthquake that struck Europe since the year 1000, the November 1, 1755 event. This earthquake generated also a destructive tsunami affecting the whole basin. This tectonically active area is crossed by the CAM (Continent-Azores-Madeira) submarine cable on a ring configuration. Due to the end of cable lifetime the current cables need to be replaced by 2024 and the technical requirements must be defined in mid-2021. The Azores archipelago is the focus of frequent seismic crizes and occasionally destructive earthquakes. A common feature of these seismic events is that they take place offshore, an area that is difficult to monitor from land-based instruments. In this work we evaluate the contribution of SMART cables to the earthquake monitoring and tsunami early warning system in SW Iberia and show how DAS and LI can improve earthquake monitoring on two active domains of the Azores. For tsunami early warning, we show how the offshore sea-level measurements provide clean offshore tsunami records when compared to coastal observations by tide gauges, which greatly improves the efficiency of the system. For earthquake monitoring, the data processing operational routine is examined using Monte-Carlo simulations. These take into consideration the errors in phase picking and the uncertainty on the 1D velocity model used for earthquake location. Quality of earthquake location is examined using the difference between the true location and the centroid of the computed epicenters and by the overall ellipse of uncertainty obtained from 100 runs. The added value provided by instrumented submarine telecommunication cables to mitigate earthquake and tsunami risk demonstrated in this work will help authorities and the society in general to take the political decisions required for its full implementation worldwide.

Parameterizing the gains in earthquake monitoring using submarine optical fiber telecom cables

<p>The need for submarine observatories to monitor offshore tectonic sources that can generate destructive earthquakes and tsunamis is widely recognized but the requirements of real-time communications and cost has hindered its Implementation. Only very few dedicated cables with sensors are in operation today. If the dozens of commercial telecommunication submarine cables that are deployed every year were instrumented, they could revolutionize the offshore earthquake monitoring. These cables, named as SMART (Science Monitoring And Reliable) have been advocated by the JTF of United Nations (Joint Task Force) for nearly a decade but none has been deployed today. However, there are several identified projects that should become the first pilots worldwide.</p><p>Fiber optic research have shown that the cable itself can be used as strain meters and useful for seismic monitoring.</p><p>One technology is DAS, Distributed Acoustic Sensing. DAS uses a single dedicated portion of (dark) fiber on a submarine cable, with a length about ~100 km. It can be modelled as a distributed strain sensor, with localization ability of a few meters. The DAS signal using OTDR (optical time domain reflectometry) and signal phase detection measures the fiber strain and record earthquakes with a resolution like broadband seismic sensors.</p><p>Another technology is LI (Laser Interferometry). LI may use a dark fiber or a single telecom wavelength channel in an optical fiber pair with commercial traffic, thousands km long. It relies on frequency stable laser sources and coherent detection. LI detects the changes of fiber optical transmission parameters over the whole cable. Using recording instruments on both ends, the arrival point of the first seismic waves is determined, and the azimuth to the epicenter estimated.</p><p>This work proposes and applies one methodology to assess the gain in earthquake source information using any of the three cable sensor technologies mentioned, against a background scenario that includes only land stations. We use a Monte-Carlo simulation to allow for picking uncertainties, local and regional variations of propagation velocity models. We parametrize the gain in information by measuring the epicenter uncertainty ellipse and the focal depth variability.</p><p>The proposed methodology is applied to the NE Atlantic domain, SW Iberia and the Azores archipelago, an area where the relative motion of the Nubia, Eurasia and North America plates can generate large and destructive earthquakes and tsunamis.</p><p>While the inclusion in the monitoring network of SMART observatories, placed inside cable repeaters, spaced every ±70 km, is straightforward, the use of DAS and LI is not. For DAS and LI we consider that observations can be decimated to virtual seismic stations every 5 km and 1 km respectively. To avoid using a set of very close stations, we implement different station selection algorithms.</p><p>The investigation presented in this work was conducted by LEA, Listening to the Earth under the Atlantic, a partnership between IT, IPMA and IDL. One of the main objectives of LEA is to promote research, development, training and outreach on geophysical and oceanographic phenomena using submarine cables, fostering its applications to Science and Civil Protection.</p>

Seismic Surveillance and Earthquake Monitoring in Italy

The Istituto Nazionale di Geofisica e Vulcanologia (INGV) is an Italian research institution with focus on earth sciences. Moreover, the INGV is the operational center for seismic surveillance and earthquake monitoring in Italy and is a part of the civil protection system as a center of expertise on seismic, volcanic, and tsunami risks.INGV operates the Italian National Seismic Network and other networks at national scale and is a primary node of the European Integrated Data Archive for archiving and distributing strong-motion and weak-motion seismic recordings. In the control room in Rome, INGV staff performs seismic surveillance and tsunami warning services; in Catania and Naples, the control rooms are devoted to volcanic surveillance. Volcano monitoring includes locating earthquakes in the regions around the Sicilian (Etna, Eolian Islands, and Pantelleria) and the Campanian (Vesuvius, Campi Fregrei, and Ischia) active volcanoes. The tsunami warning is based on earthquake location and magnitude (M) evaluation for moderate to large events in the Mediterranean region and also around the world. The technologists of the institute tuned the data acquisition system to accomplish, in near real time, automatic earthquake detection, hypocenter and magnitude determination, and evaluation of several seismological products (e.g., moment tensors and ShakeMaps). Database archiving of all parametric results is closely linked to the existing procedures of the INGV seismic surveillance environment and surveillance procedures. Earthquake information is routinely revised by the analysts of the Italian seismic bulletin. INGV provides earthquake information to the Department of Civil Protection (Dipartimento di Protezione Civile) to the scientific community and to the public through the web and social media. We aim at illustrating different aspects of earthquake monitoring at INGV: (1) network operations; (2) organizational structure and the hardware and software used; and (3) communication, including recent developments and planned improvements.