Scholarlink

<p>The China Earthquake Administration (CEA) has launched an ambitious nationwide earthquake early warning (EEW) system project, now fully operational as of July 2024. This system, the largest EEW network in the world, comprises approximately 15,000 seismic stations. In approximately 50%, 30% and 20% of Chinese mainland, the inter-station distance will soon be smaller than 50&#xa0;km, 25&#xa0;km and 15&#xa0;km, respectively. The expected effectiveness of this EEW system can be quantified via the metric determined from the radius of the blind zone, which refers to the area near the epicenter where there is insufficient time to issue a warning before the arrival of strong <i>S</i>- and surface waves. This study uses a theoretical network-based method together with Monte Carlo simulation to obtain the spatial distribution of the blind zone radii and their associated uncertainties for the new seismic network based on its configuration. We find that the densified new seismic network is expected to have excellent EEW performance as the area covered by small blind zones with a radius ≤ 30&#xa0;km increases dramatically from approximately 2–22%, that is by 2.4&#xa0;million km<sup>2</sup> inside Chinese mainland. This improvement reduces regions affected by large blind zones and translates into substantial gains in lead time (available warning time). Compared to the previous network layout, lead times are expected to increase by approximately 20&#xa0;s, 10&#xa0;s, and 5&#xa0;s for approximately 50%, 30%, and 10% inside Chinese mainland, respectively. We also conducted a preliminary cost-outcome evaluation of the new EEW system from the perspective of blind zones. Continuing to increase the density of stations in some key regions with blind zone radii ranging from 15 to 40&#xa0;km is still necessary to control the unexpected expansion of blind zones due to possible (and common) stations failure. Our work provides insights into the expected performance of the upcoming EEW network in Chinese mainland, and our proposed evaluation approach is broadly applicable for predicting the performance of EEW systems during their planning, design, and implementation stages.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Estimating earthquake early warning effectiveness via blind zone sizes: a case study of the new seismic network in Chinese mainland

  • 期刊论文

  • 发表日期：

    2025年1月16日

查看全文
  • Jiawei Li,
  • Didier Sornette,
  • Yu Feng

摘要

The China Earthquake Administration (CEA) has launched an ambitious nationwide earthquake early warning (EEW) system project, now fully operational as of July 2024. This system, the largest EEW network in the world, comprises approximately 15,000 seismic stations. In approximately 50%, 30% and 20% of Chinese mainland, the inter-station distance will soon be smaller than 50 km, 25 km and 15 km, respectively. The expected effectiveness of this EEW system can be quantified via the metric determined from the radius of the blind zone, which refers to the area near the epicenter where there is insufficient time to issue a warning before the arrival of strong S- and surface waves. This study uses a theoretical network-based method together with Monte Carlo simulation to obtain the spatial distribution of the blind zone radii and their associated uncertainties for the new seismic network based on its configuration. We find that the densified new seismic network is expected to have excellent EEW performance as the area covered by small blind zones with a radius ≤ 30 km increases dramatically from approximately 2–22%, that is by 2.4 million km2 inside Chinese mainland. This improvement reduces regions affected by large blind zones and translates into substantial gains in lead time (available warning time). Compared to the previous network layout, lead times are expected to increase by approximately 20 s, 10 s, and 5 s for approximately 50%, 30%, and 10% inside Chinese mainland, respectively. We also conducted a preliminary cost-outcome evaluation of the new EEW system from the perspective of blind zones. Continuing to increase the density of stations in some key regions with blind zone radii ranging from 15 to 40 km is still necessary to control the unexpected expansion of blind zones due to possible (and common) stations failure. Our work provides insights into the expected performance of the upcoming EEW network in Chinese mainland, and our proposed evaluation approach is broadly applicable for predicting the performance of EEW systems during their planning, design, and implementation stages.