Tectonic plate interactions in Sumatra have caused a range of devastating earthquake events. In this study, we develop an analytical framework, known as earthquake nowcasting (Rundle et al. in Earth and Space Science 3:480–486, 2016. 10.1002/2016EA000185), to assess the current dynamical state of earthquake hazards in Sumatra and adjacent islands from the empirical distribution of natural times, the cumulative counts of “small” events (say, M ≥ 4) between two successive “large” earthquakes (say, M ≥ 6.5). Based on 50 years of instrumental earthquake data, the best fit Weibull distribution assigns earthquake potential score between 29 and 96% to 19 large cities in the study region with the values (%) of Aceh (72), Bengkulu (34), Binjai (81), Jambi (35), Lahat (29), Lampung (45), Lhoksuemawe (54), Medan (75), Mentawai (76), Meulaboh (71), Nias (95), Palembang (80), Padang (74), Pekanbaru (39), Sabang (72), Siantar (82), Sibolga (92), Sinabang (96), and Tanjung Balai (55). These areal-source based nowcast scores, analogous to the tectonic stress buildup since the last major event, essentially provides a unique characterization of the current level of seismic progression of a city through its repetitive cycle of regional earthquakes. Inclusion of dependent events with aftershocks being more common and the concept of natural times are some of the distinctive advantages of the proposed method. The resulting natural time statistics and consequent earthquake potential scores will facilitate seismic risk estimation, multistate decision-making, and community awareness, leading to an efficient seismic risk reduction strategy in the densely populated study region.

苏门答腊的构造板块相互作用引起了一系列毁灭性的地震事件。在这项研究中，我们建立了一个分析框架，即地震临近预报（Rundle等人，Earth and Space Science 3：480–486，2016. 10.1002 / 2016EA000185），以评估苏门答腊及周边地区地震灾害的当前动态状态从天然倍经验分布岛屿，“小”的事件的累积计数（比方说，中号 的两个连续的“大”地震之间≥4）（比方说，中号 ≥6.5）。根据50年的仪器地震数据，最合适的Weibull分布将研究区域内19个大城市的地震潜在得分分配在29％至96％之间，其中Aceh（72），Bengkulu（34），Binjai（ 81），占碑（35），拉哈特（29），楠榜（45），罗克苏玛（54），棉兰（75），曼塔怀（76），默拉波（71），尼亚斯（95），巨港（80），巴东（ 74），北干巴鲁（39），萨邦（72），锡安塔尔（82），西博加（92），锡那邦（96）和丹戎巴莱（55）。这些基于面源的临近预报分数，类似于自上次重大事件以来的构造应力累积，从本质上提供了城市通过其区域性地震的重复周期而得出的当前地震进展水平的独特特征。所涉及的方法包括余震在内的相依事件更为常见，以及自然时间的概念是所提出方法的一些独特优势。由此产生的自然时间统计数据和随之产生的地震潜在得分将有助于地震风险评估，多州决策制定和社区意识，从而在人口稠密的研究区域内实现有效的地震风险降低策略。