The Hengchun earthquake doublet off southern Taiwan

Assembled from 22 blocks · 2 evidence · 17 related

1. Story
2. Two earthquakes struck in the Luzon Strait off Hengchun at the southern tip of Taiwan, eight minutes apart: the first at 12:26 UTC at magnitude about 7.0, the second at 12:34 UTC at about 6.9, at focal depths of the order of 44 and 50 km. They were the largest events recorded in south-western Taiwan in a century. A small tsunami was recorded on nearby tide gauges. The seismic damage on land was comparatively limited; what made the event globally significant happened on the seabed, where the shaking set submarine landslides and sediment density flows moving down the canyon system toward the Manila Trench.
3. Knowledge
4. The Luzon Strait
5. The turbidity current
6. The Hengchun earthquake doublet off southern Taiwan
7. Connections
8. The Luzon Strait
9. The turbidity current
10. Cables in the Luzon Strait break in sequence over nine hours
11. Taiwan
12. The cable chokepoint
13. The Hengchun earthquake doublet off southern Taiwan
14. Cables in the Luzon Strait break in sequence over nine hours
15. East Asian connectivity degrades for weeks
16. The Grand Banks earthquake breaks cables in sequence
17. The Hengchun earthquake doublet off southern Taiwan
18. Cables in the Luzon Strait break in sequence over nine hours
19. Four cables fail off Côte d'Ivoire and thirteen countries lose connectivity
20. Evidence
21. Supports the timing, magnitudes and focal depths used here: a first event at 12:26:21 UTC on 26 December 2006 at about magnitude 7.0 and a second at 12:34:15 UTC at about 6.9, at focal depths of roughly 44 and 50 km, with a small recorded tsunami. V55 verification basis: NOT read; the parameters were carried by retrieved search results attributing them to the Central Weather Bureau catalogue as reported in that literature. Reported magnitudes for these events vary between catalogues, which is normal and is why approximate values are used here.
22. Supports the account of the 2006 Luzon Strait cable failures as a sequential process driven by earthquake-triggered sediment density flows running down submarine canyons into the Manila Trench, with flow speeds of several metres per second inferred from break timings. V55 verification basis: NOT read; retrieved in summary only. Published break counts for the 2006 event differ between analyses — eight, nine, eleven, thirteen and twenty-two all appear — and this pack states the range rather than adopting one.