Clinoform features and geohazard implications of subaqueous delta offshore Zhoshui River, Eastern Taiwan Strait
Journal
Episodes
Journal Volume
49
Journal Issue
2
Start Page
161
End Page
171
ISSN
0705-3797
2586-1298
Date Issued
2026-06-01
Author(s)
Chang, Sung-Ping
Lin, Liang-Fu
Shih, Bo-Hao
Wang, Yi-Hao
Chen, Yi-Ping
Ma, Yu-Fang
Abstract
The Zhoshui River, the largest fluvial system in Taiwan, delivers ≈ 30 - 60Mt of sediment annually westward to the Taiwan Strait, yet its offshore continuation and related nearshore stability remain poorly constrained amid growing offshore engineering activities along western Taiwan. Here we use three high-resolution sparker seismic profiles and regional bathymetry to investigate the seaward extension of the Zhoshui River fan delta in the eastern Taiwan Strait. Bathymetry shows a pronounced alongshore narrowing of the 20 - 30m isobath spacing from ≈ 5km offshore of the river mouth to ≈ 1km farther north, coinciding with the development of distinct bathymetric rollovers. The sparker seismic profiles consistently image a two-tier clinoform architecture, comprising a northward-thinning upper sequence and a lower sequence with well-developed topset-forest-bottomset geometry. These observations suggest a compound delta formed by interaction between river-derived sediment supply and alongshore redistribution. Beneath the subaqueous-delta front, laterally extensive acoustically transparent facies are observed, suggesting subsurface sediment disturbance related to elevated pore-water pressures and possible liquefaction-related processes. These results provide a geological framework for evaluating nearshore sediment instability and liquefaction-related geohazards offshore western Taiwan.
Subjects
Taiwan Strait
bathymetry
fluvial deposit
geological hazard
liquefaction
seismic method
Publisher
International Union of Geological Sciences
Type
journal article