The Ethiopian rift which is part of East African Rift system passes through the middle of the country making it one of the most seismically active regions in the world. Thus, significant and damaging earthquakes have been reported and recorded in the past in this region. A homogeneous earthquake catalog is of basic importance for studying the earthquake occurrence pattern in space and time and for many engineering applications including assessment of seismic hazard, estimation of peak ground accelerations and determination of long-term seismic strain rates. The first earthquake catalogue for Ethiopia was prepared by Pierre Gouin and later, different authors attempted to compile a catalogue using different time period intervals and different earthquake magnitude scales. The b-value mapping and its implication never done for Ethiopia and its environs. The main purpose of the study is therefore first compile and homogenize earthquake catalog of Ethiopia including Read Sea and Gulf of Aden regions into Moment magnitude Mw scale through completeness analysis in time and magnitudes. Secondly, mapping b-values for different Seismgenic regions and understand its implications for magma induced Seismicity in the regions. During the present study, a new homogenized earthquake catalog in moment magnitude scale (Mw), covering about 3814 events is prepared for Ethiopia including Red sea and Gulf of Aden regions. The present study area is bounded within Latitude (40N − 200)N and Longitude (340N − 480)N E and have a magnitude range of Mw (3.0–7.1) with a total coverage period of 56 years (1960 to 2016). The catalog has been analyzed for magnitude completeness (Mc) using Gutenberg’s Frequency Magnitude Distribution law and it is found to be complete respectively for Mc ≥ 4.6 ± 0.03, Mc ≥ 4.6 ± 0.03, Mc ≥ 3.2, Mc ≥ 3.1 and Mc ≥ 5.1 for Afar including red sea and Gulf of Aden, Afar rift and Dabbahu Volcano, Northern, Central, and Southern Main Ethiopian Rifts. Further, the corresponding average b-value of the regions Afar including Red Sea and Gulf of Aden, Afar and Dabbahu Volcano separately, Northern Main Ethiopian Rift, Central Main Ethiopian Rift and Southern Main Ethiopian Rift respectively are estimated to be 1.17 ± 0.05, 1.15 ± 0.05, 0.843, 0.826 and 1.03 with respective period of completeness from 2003 to 2014, 2005 to 2014, 2001 to 2003, 2001 to 2003 and 1960 to 2016 for the regions. Later, mapping of the b-values in the Gutenberg-Richter relation from the newly developed catalog was performed by binning the regions into minimum of 0.050x0.050 for Afar and Dabbahu region, 0.10x0.10 for Main Ethiopian rifts and 0.20x0.20 for the other regions. Thus, the b-value characteristics of various seismogenic zones within the area have been discussed. Hence, in this study, we clearly observed that magma chamber movement including mapping of volcanic centers and magmatic segments are mapped using b-values.

中文翻译：

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埃塞俄比亚及其毗邻地区的均质地震目录和b值映射

作为东非裂谷系统一部分的埃塞俄比亚裂谷穿过该国中部，使其成为世界上地震最活跃的地区之一。因此，该地区过去曾报道并记录了重大的破坏性地震。均匀的地震目录对于研究时空中的地震发生模式以及许多工程应用（包括评估地震危险，估算地面加速度峰值和确定长期地震应变率）具有至关重要的意义。埃塞俄比亚的第一个地震目录是由Pierre Gouin编写的，后来，不同的作者尝试使用不同的时间间隔和不同的地震震级来编制目录。b值映射及其含义从未对埃塞俄比亚及其周围地区产生影响。因此，这项研究的主要目的是首先通过时间和震级的完整性分析，将埃塞俄比亚包括雷德海和亚丁湾地区在内的地震目录编成矩量级Mw规模并将其均匀化。其次，绘制不同震源区的b值，并了解其对这些地区岩浆诱发地震的影响。在本研究中，为埃塞俄比亚（包括红海和亚丁湾地区）准备了一个新的地震矩量表（Mw），涵盖了3814个事件。本研究区域的范围为纬度（40N-200）N和经度（340N-480）NE，其震级范围为Mw（3.0-7.1），总覆盖期为56年（1960年至2016年）。已使用古登堡频率幅值分布定律对目录进行了幅度完整性（Mc）分析，发现分别对于Mc≥4.6±0.03，Mc≥4.6±0.03，Mc≥3.2，Mc≥3.1和Mc≥5.1是完整的远方包括红海和亚丁湾，远方裂谷和达巴胡火山，北部，中部和南部埃塞俄比亚大裂谷。此外，估计分别包括红海和亚丁湾，阿法尔和达巴胡火山，北部埃塞俄比亚大裂谷，中央埃塞俄比亚大裂谷和南部埃塞俄比亚大裂谷在内的阿法尔地区相应的平均b值分别为1.17±0.05、1.15区域的完整期分别从2003年至2014年，2005年至2014年，2001年至2003年，2001年至2003年以及1960年至2016年分别为±0.05、0.843、0.826和1.03。后来，通过将区域划分为Afar和Dabbahu地区的0.050x0.050，主要埃塞俄比亚裂谷的0.10x0.10和0.20x0.20的区域，对新开发的目录中的Gutenberg-Richter关系中的b值进行映射其他地区。因此，已经讨论了该区域内各种地震发生带的b值特征。因此，在这项研究中，我们清楚地观察到岩浆室运动（包括火山中心和岩浆段的映射）是使用b值映射的。