A spatial statistical analysis of the occurrence of earthquakes along the Red Sea floor spreading: clusters of seismicity

Al-Ahmadi, Khalid; Alamri, Abdullah; See, Linda

doi:10.1007/s12517-013-0974-6

Cited by 39 publications

(24 citation statements)

References 33 publications

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“…This resulted in predicted emission rates for ethane (0.12 ± 0.06 Tg yr −1 ), propane (0.12 ± 0.06 Tg yr −1 ), i-butane = 0.03 ± 0.03 Tg yr −1 , and n-butane = 0.07 ± 0.06 Tg yr −1 (uncertainties are based on the standard deviation of the measurement/ model ratio values within the 25th and 75th percentile). Increasing uncertainties will be introduced when considering the seasonality of the deep-water circulation, the wind speeds at the air-sea interface, and the potential temporal variability of the emissions (i.e., triggered events by the increased seismic activity in the region 48 ). As a final step, the derived emission rates were added to the model and the simulations were repeated.…”

Section: Resultsmentioning

confidence: 99%

The Red Sea Deep Water is a potent source of atmospheric ethane and propane

et al. 2020

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Non-methane hydrocarbons (NMHCs) such as ethane and propane are significant atmospheric pollutants and precursors of tropospheric ozone, while the Middle East is a global emission hotspot due to extensive oil and gas production. Here we compare in situ hydrocarbon measurements, performed around the Arabian Peninsula, with global model simulations that include current emission inventories (EDGAR) and state-of-the-art atmospheric circulation and chemistry mechanisms (EMAC model). While measurements of high mixing ratios over the Arabian Gulf are adequately simulated, strong underprediction by the model was found over the northern Red Sea. By examining the individual sources in the model and by utilizing air mass back-trajectory investigations and Positive Matrix Factorization (PMF) analysis, we deduce that Red Sea Deep Water (RSDW) is an unexpected, potent source of atmospheric NMHCs. This overlooked underwater source is comparable with total anthropogenic emissions from entire Middle Eastern countries, and significantly impacts the regional atmospheric chemistry.

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Section: Resultsmentioning

confidence: 99%

The Red Sea Deep Water is a potent source of atmospheric ethane and propane

et al. 2020

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“…Much of the seismicity of this region is of the swarm type and is related to subsurface volcanic activities (El-Isa and Al -Shanti 1989; Al-Amri 1995b; Daggett et al 1986;Al-Amri et al 1998;Gharib 1999;Badawy and Abdel-Fattah 2006). Many researchers believe that the seismicity of the northern part of the Red Sea north of latitude 21°N is actually lower than that of the southern part (e.g., Pedone et al 1992;Al-Amri 1995a;Al-Amri et al 1998;Gharib 1999;Al-Ahmadi et al 2013). El-Isa and Al-Shanti (1989) referred to only an apparent lower activity in the northern part.…”

Section: Introductionmentioning

confidence: 99%

Seismicity and seismotectonics of the Red Sea Region

El-Isa

2015

Arab J Geosci

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The historical seismicity of the Red Sea region between latitudes 13 and 30°N and longitudes 32 and 46°E has been revised. It is found that during the last 1400 years, some 88 historical earthquakes have occurred with magnitudes M≥ 5.6. Only two M=7.0 are reported, one in each of the northern and southern Red Sea regions, followed by two and one 6.8 in the northern and southern regions, respectively. During the period 1960-2010, some 1310 instrumental earthquakes have occurred in the region with M≥4.0. The largest (M=7.1) occurred in the Gulf of Aqaba, followed by a 6.9 in the entrance of the Gulf of Suez, followed by a 6.7 and a 6.4 that occurred in the southern Red Sea region. All others had M≤6.2. More than 90 % of the seismicity has occurred in the form of sequences and swarms and are believed to be volcanic related. Thus, the seismic hazard of the study region remains quite limited. Both northern and southern parts of the Red Sea region are of comparable seismic activities, while that of the central part is of lower activity. The historical and instrumental seismicity data show excellent correlation with the general tectonics of the study region. These also show that earthquake activity has fluctuated with time from one region to the other. In the Red Sea proper, more than 83 % of the seismic moment is associated with the regional faults of the axial trough with noticeable concentration of activity where the NE trending strike-slip faults cross this trough. Published fault plane solutions for the largest instrumental earthquakes of the last few decades show that both normal and strike-slip faults are active in support of a divergent environment between the Arabian and African plates. Shallow seismicity is a characteristic feature of this region. The data indicates that lithospheric deformations beneath the gulfs area are restricted to the upper part of the crust, while beneath the Red Sea south of latitude 27.8°, these appear to concentrate partially within the crust down to 10 km depth and much more within the uppermost mantle, mostly from 20.1 to 40 km depths. Very little earthquakes occur at depths deeper than 60 km. Frequency-magnitude results of both historic and instrumental data gave the expected b value close to 1.0. The calculated recurrence periods for earthquakes with M=6, 6.5 and 7 are 30±2 years, 150± 10 years and 600±20 years, respectively. The data show that the threshold magnitude for the study region is 4.0, and slightly more for the axial trough.

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“…Kernel Density Estimation (KDE) is a non-parametric spatial interpolation method which analyzes the nature of the first orde from distribution point by calculating the density (Silvermen, 1986).The general form of KDE functions on two-dimensional plane is: 6Where λ (s) is the density at location s, r is the radius or bandwidth of KDE, n is the number of sample points, and k is the weight of point i on distance d is to location s. Surface value is the value of the location point minus the distance from the point, close to zero at the radius point. The variable k is usually modeled as a function of the ratio between the kernel and r. KDE is applied for research that produces a continuous surface map on the quake density based on the location and the value of the quake, where the density of a location reflects the concentration of earthquakes in the surrounding area (Ahmadi et al, 2014).…”

Section: Kernel Density Estimationmentioning

confidence: 99%

Spatial Statistic Analysis of Earthquakes in Aceh Province Year 1921-2014: Cluster Seismicity

Affan¹,

Syukri²,

Wahyuna³

et al. 2016

Aceh Int. J. Sci. Technol

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The purpose of this study is to apply the analysis of spatial patterns of earthquakes in the province of Aceh by detecting clusters and looking for spatial patterns locally and globally during the period 1921-2014 using GIS (Geographic Information System). The selected techniques are Average Nearest Neighbor, Moran Global Index, the Getis-Ord General G, Anselin Local Moran Index, the Getis-Ord Gi*, and Kernel Density Estimation. Each technique is implemented using GIS so that calculations can be done efficiently and quickly. The results of this study indicate that (1) The techniques can detect clusters of dots on the spatial pattern of earthquakes; (2) Both globally and locally, it shows that earthquakes clustered in the southwestern heading to the northern part of the province; (3) An earthquake with a greater magnitude generally concentrated in the district of Simeulue, the western part of Aceh Besar and northwest of Sabang

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A spatial statistical analysis of the occurrence of earthquakes along the Red Sea floor spreading: clusters of seismicity

Cited by 39 publications

References 33 publications

The Red Sea Deep Water is a potent source of atmospheric ethane and propane

The Red Sea Deep Water is a potent source of atmospheric ethane and propane

Seismicity and seismotectonics of the Red Sea Region

Spatial Statistic Analysis of Earthquakes in Aceh Province Year 1921-2014: Cluster Seismicity

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