Spectral acceleration is representative of seismic hazard in modern building codes as well as an important parameter used in seismic design these days. Karachi, an economic artery of Pakistan, is located in the vicinity of an active tectonic setting, i.e., triple junction, with uncertain seismicity. Keeping in view the modern seismic design practices, efforts are required to evaluate the seismic hazard of Karachi city in terms of spectral acceleration. This study is focused on the estimation of seismic hazard for the metropolitan city of Karachi in the context of modern building codes. The seismic potential of around 800–900-km circle was considered a threat for the city, and 13 seismic zones (A-1 to A-13) were identified as seismic sources. A seismicity model based on Gutenberg-Richter law was developed, identifying A-1 and A-11 as zones of high seismicity. The ground attenuation model recommended for the Middle East region proposed by Akkar and Bommer was utilized for the computation of different ground motion scenarios. Short-period, S_S, and 1-s, S₁, spectral acceleration values for considered region were calculated as 1.37 m/s² and 0.41 m/s², respectively. In addition, peak ground acceleration (PGA) values for Karachi city were observed to be in a range of 0.7–0.77 m/s². The results of this study provide bases for the preparation of seismic risk maps, the estimation of earthquake insurance premiums, seismic zonation for region lying on Arabian and Indian plates, and the preliminary site evaluation of critical facilities.

频谱加速度代表了现代建筑规范中的地震危害，同时也是当今抗震设计中使用的重要参数。巴基斯坦的经济大国卡拉奇位于活跃的构造环境附近，即三重交界处，地震活动不确定。结合现代地震设计实践，需要努力从频谱加速度方面评估卡拉奇市的地震危害。这项研究的重点是在现代建筑规范的背景下估算大都市卡拉奇的地震危害。大约800-900公里圈的地震潜力被认为对该城市构成威胁，并确定了13个地震带（A-1至A-13）作为地震源。建立了基于古腾堡-里希特定律的地震活动模型，确定A-1和A-11为高地震活动区。Akkar和Bommer建议的中东地区推荐的地面衰减模型用于计算不同的地面运动场景。短期内，S _S和1-s，S ₁，所考虑区域的光谱加速度值分别计算为1.37 m / s ²和0.41 m / s ²。此外，卡拉奇市的地面加速度峰值（PGA）值在0.7-0.77 m / s ²的范围内。研究结果为地震风险图的编制，地震保险费的估算，阿拉伯和印度板块区域的地震分区以及关键设施的初步现场评估提供了基础。