Focal depth, magnitude, and frequency distribution of earthquakes along oceanic trenches

Hammed, O.S.; Popoola, O. I.; Adetoyinbo, A.A.; Awoyemi, Musa Olufemi; Badmus, Ganiyu Olabode; Ohwo, O. B.

doi:10.1007/s11589-013-0021-4

Cited by 6 publications

(5 citation statements)

References 11 publications

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“…The b-value is the stress meter that indicates the level of tectonic stress accumulation in the earthquake-prone zones, Hammed et al (2019). The lower the b-value, the higher the tectonic stress and vice-versa (Awoyemi et al 2017;Hammed et al 2013). In this work, the b values obtained in all https://doi.org/10.5194/nhess-2020-128 Preprint.…”

Section: Trend Of Seismicity and Tectonic Characterization Along The mentioning

confidence: 67%

Evaluation of global seismicity along Northern and Southern hemispheres

Hammed

Adagunodo

Awoyemi

et al. 2020

Preprint

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Abstract. An earthquake has been identified as one of the major natural disasters that cause loss of lives and property. To mitigate this disaster, knowledge of global seismicity is essential. This research is aimed at evaluating the Gutenberg Richter b-value parameter and focal depth distribution of earthquake parameters to identify the prominent earthquake-prone zones in the Northern and Southern hemispheres. The study area covers 20° to the Northern and Southern hemispheres, with the equator in the middle. The data were obtained from the earthquake catalogue of the Advanced National Seismic System (ANSS) hosted by the Northern California Earthquake Data Centre USA from 1963–2018. Fifty-four-year earthquake data of M ≥ 6.0 were processed and analyzed using Gutenberg-Richter (GR). The b-value parameters obtained from the GR model were plotted against the hemispheres using bar chart graphs to determine the tectonic stress level of the study region. The earthquake energy released was evaluated along the Northern and Southern hemispheres for a proper understanding of seismic events in the study region. It was observed that the rate of earthquake occurrence at the Southern hemisphere is higher than the Northern hemisphere. The b-values obtained in all the zones vary from 0.82–1.16. At the same time, the maximum earthquake energy of 4.6 × 1025 J was estimated. Low b-values indicate high tectonic stress within the plates. The large tectonic stress accumulation around the equator suggests that unstable lithospheres characterize this zone.

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Section: Trend Of Seismicity and Tectonic Characterization Along The mentioning

confidence: 67%

Evaluation of global seismicity along Northern and Southern hemispheres

Hammed

Adagunodo

Awoyemi

et al. 2020

Preprint

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“…The focus of an earthquake is the actual point where the rocks break in the subsurface. The depths of the focus are categorized as shallow (0–70 km), intermediate (71–300 km), and deep depth (301–700 km below the earth surface) respectively [8] . Most earthquakes occurred at shallow depth, with total events of 76223, while deep depth had a total record of 61 times, with the magnitude ranging from 2 to 4.9.…”

Section: Experimental Design Materials and Methodsmentioning

confidence: 99%

“…The descriptive analysis has also been found useful in the evaluation of earthquake occurrence in a region. This ranged from description of earthquake occurrence by plotting the graphs of frequencies of earthquakes against their coordinates [5] , number of earthquakes against its magnitudes [7] , [8] , cumulative number of earthquake against its magnitude [7] , and measure of central tendencies [9] . It has been reported that study of previous and present activities of earthquake pattern is vital in prevention of lives and properties from earthquake destructions [9] .…”

Section: Datamentioning

confidence: 99%

Evaluation of 0 ≤ M ≤ 8 earthquake data sets in African – Asian region during 1966–2015

et al. 2018

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This article evaluates the occurrence of 0 ≤M≤ 8 earthquake data sets for the period of 50 years (that is, January 1, 1966 to December 31, 2015) in African and Western Asia region. It is bounded by latitude 40° S to 40° N and longitude 30° W to 60° E with the focal depth of 0–700 km. Seventy seven thousand, six hundred and ninety-six data points were presented for the analysis. The data used were extracted from earthquake catalog of Advanced National Seismic system via http://quake.geo.berkeley.edu/cnss/, an official website of the Northern California Earthquake Data Centre, USA. Each datum comprised the earthquake occurrence date, time of the earthquake occurrence, epicenter’s coordinates, focal depth and magnitude. The Gutenberg-Richter’s relationship being the longest observed empirical relationship in seismology, analysis of variance and time series were used to analyze the seismicity of the study area. Annual distributions of earthquake occurrence based on magnitude variations with the limit 0 ≤M≤ 8 were presented. The two constants a and b in the Gutenberg-Richter’s equation, magnitude of completeness (MC) adjusted R-Square and F-value for the period of 1966–1975, 1976–1985, 1986–1995, 1996–2005, 2006–2015, and the entire period of investigation ranging from 1966 to 2015 were determined so as to investigate the variations of these parameters on earthquake occurrence over time. The histograms of earthquake occurrence against magnitude of earthquakes for the selected years (1966–1975, 1976–1985, 1986–1995, 1996–2005, 2006–2015, and 1966–2015), and the decadal frequency distributions of earthquake occurrence were also plotted. The focal depth occurrence for each magnitude bins (0–0.9, 1–1.9, 2–2.9, 3–3.9, 4–4.9, 5–5.9, 6–6.9, 7–7.9, 8–8.9) were grouped into shallow, intermediate, and deep depths ranging from 0 to 70, 71 to 300, and 301 to 700 km as being used in seismology. The neural network analysis was also applied to the magnitude of the earthquake. The network uses a time series magnitude data as input with the output being the magnitude of the following day. If the nature of the earthquakes time series is stochastic, modeling and prediction is possible. The earthquake data sets presented in this article can further be adopted in the study of seismicity pattern, b-value using series of models, earthquake prediction and variations of earthquake parameters on African and/or Arabian plates. When this approach is integrated with other technique(s), it can provide insights to stability of African lithospehric plates especially the coastal region of Africa.

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“…This earthquake caused heavy damage and many casualties within villages more than 10 kilometers from the epicenter (Boyd et al, 2007b). and deep-focus earthquakes are 300 to 700 km (Hammed et al, 2013). Intermediate-depth earthquakes represent deformation within the subducted lithosphere beneath the Eurasian Plate, rather than shallow plate interfaces between subducting and overriding tectonic plates.…”

Section: Manuscript Submitted To Earth's Futurementioning

confidence: 99%

Earthquake Risks and Lack of Disaster Management in Afghanistan

Akhundzadah

2023

Preprint

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Afghanistan is in a seismically active area and is historically hit by destructive earthquakes. It is located on the edge of the Eurasian tectonic plate, bordered by the northern boundary of the Indian plate, and with the collisional Arabian plate into the South. The Hindukush and Pamir Mountains within Afghanistan are the western extension of the Himalayan orogeny uplifted and sheared by Indian and Eurasian plate convergence. These tectonic activities have created several active deep faults across the country and in the Hindukush-Himalayan region, where high-magnitude earthquakes have historically occurred. Earthquakes in Afghanistan are primarily driven by the relative northward movements of the Arabian plate past western Afghanistan and the Indian plate past eastern Afghanistan as both plates subduct under the Eurasian plate. These tectonic movements caused ground shaking from high to moderate and low from the northeast through the southwest of the country. On June 22, 2022, southeastern part of Afghanistan was hit by a destructive Mw6.2 earthquake. The purpose of this study is to develop an ArcGIS Pro database of compiled geologic faults and regions of heightened seismicity for spatial analyses of earthquake disaster severity across Afghanistan. These spatial analyses place better constraints on the placement of active and historic seismicity along mapped and known active faults for progress in earthquake disaster management. Furthermore, we define current hazards associated with building and infrastructural design and competency given the recurrent and eminent seismicity within Afghanistan and describe possible directions and solutions to mitigate the threat to life and property.

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Focal depth, magnitude, and frequency distribution of earthquakes along oceanic trenches

Cited by 6 publications

References 11 publications

Evaluation of global seismicity along Northern and Southern hemispheres

Evaluation of global seismicity along Northern and Southern hemispheres

Evaluation of 0 ≤ M ≤ 8 earthquake data sets in African – Asian region during 1966–2015

Earthquake Risks and Lack of Disaster Management in Afghanistan

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