Showing papers by "Central Geological Survey, MOEA published in 2020"
TL;DR: Sediment cores distributed across a submarine mud volcano (SMV) offshore southwestern Taiwan were investigated to determine the characteristics of fluids generated through the convergence between the Eurasian and Phillippine Sea Plates, implying that SMVs could act as a conduit to channel the fluids produced from great depth/temperature into seafloor environments in a subduction system of the western Pacific Ocean.
Abstract: Qualitative and quantitative assessments of fluid cycling are essential to address the role and transport of deeply sourced fluids in subduction systems. In this study, sediment cores distributed across a submarine mud volcano (SMV) offshore southwestern Taiwan were investigated to determine the characteristics of fluids generated through the convergence between the Eurasian and Phillippine Sea Plates. The low dissolved chloride concentration combined with the enrichment of 18O, and depletion of 2H of pore fluids suggest the discharge of deep freshwater formed by smectite dehydration at an equilibrium temperature of 100 to 150 °C. The upward fluid velocities, decreasing from 2.0 to 5.0 cm yr−1 at the center to a negligible value at margin sites, varied with the rate and efficiency of anaerobic methanotrophy, demonstrating the impact of fluid migration on biogeochemical processes and carbon cycling. By extrapolating the velocity pattern, the flux of fluids exported from 13 SMVs into seawater amounted up to 1.3–2.5 × 107 kg yr−1, a quantity accounting for 1.1–28.6% of the smectite-bound water originally stored in the incoming sediments. Our results imply that SMVs could act as a conduit to channel the fluids produced from great depth/temperature into seafloor environments in a subduction system of the western Pacific Ocean.
16 citations
TL;DR: The southern Sanyi Fault is a low-angle thrust that juxtaposes poorly lithified sandstone over alluvial gravels as discussed by the authors, and the fault branches are common both in the hanging wall and footwall.
9 citations
TL;DR: In this article, the authors proposed a conceptual model which simultaneously illustrates the hydrothermal circulation pattern from the previous general surveys and the enormous thermal anomaly from detailed measurements around the Geolin Mound (GLM) (24° 36.6 ‘N, 122° 53’E).
8 citations
02 Nov 2020
TL;DR: Wang et al. as discussed by the authors used logistic regression to evaluate landslide susceptibility and established the assessment method of the rainfall threshold of landslide by using I3-R24 rainfall thresholds, which are a reference of preparation for slope disasters.
Abstract: In this study, the development of landslide susceptibility and determination of rainfall threshold for shallow landslides is the main purpose for the prevention of slope disaster. For appliance of the practical operation of disaster prevention, almost 185,000 slope units are used to calculate landslide susceptibility and determine the rainfall threshold of shallow landslides, which are a reference of preparation for slope disasters. Time of occurrence of 941 landslides are collected through field investigation, and rainfall pattern of each landslides are analyzed to clarify the relation between landslide and rainfall. Logistic regression (LR) analysis was performed to evaluate landslide susceptibility and establish the assessment method of the rainfall threshold of landslide by using I3–R24 rainfall thresholds. After verification of rainfall-induced landslide in Typhoon Meranti (2016), the result show that the early warning model is suitable for alerting serious swarm of landslides.
3 citations
27 Jul 2020
TL;DR: This paper reported new noble gas signatures of groundwaters, hot springs, and bedrock samples from two major fault systems that form the plate boundary suture between the Eurasian Plate and the Philippines.
Abstract: We report new noble gas signatures of groundwaters, hot springs, and bedrock samples from two major fault systems that form the plate boundary suture between the Eurasian Plate and the Philippines ...
1 citations