Showing papers by "Central Geological Survey, MOEA published in 2014"
TL;DR: In this article, the authors combine the results of detailed field investigation and process-based as well as empirical-based method to point out unsafe road sections for mitigating rockfall impact, reducing similar disasters in this area.
54 citations
TL;DR: Authigenesis of iron-rich phosphate nodules occurs in ironrich cold-seep sediments (MD052911 core) at Yung-An Ridge offshore southwestern Taiwan as mentioned in this paper.
41 citations
TL;DR: In this paper, reflection seismic and bathymetric data were used to infer the canyon-infilling, fold uplift, and gas hydrate occurrences beneath the frontal fold at the toe of the accretionary wedge, offshore SW Taiwan.
Abstract: We utilized reflection seismic and bathymetric data to infer the canyon-infilling, fold uplift, and gas hydrate occurrences beneath the frontal fold at the toe of the accretionary wedge, offshore SW Taiwan. The lateral migrating paleo-Penghu canyons has cut across the frontal fold with six distinct canyon/channel incisions marked by channel infills. The longitudinal bathymetric profile along the modern canyon course shows a knickpoint of ~300 m relief at this frontal fold, indicating that the rate of fold uplift is greater than that of canyon incision. The age for the initial thrusting of this fontal fold is around 240 kyr ago, as estimated by using the maximum thickness of growth strata of this fold divided by the sedimentation rate obtained from a nearby giant piston core. Bottom simulating reflector (BSR) on seismic sections indicates the base of gas hydrate stability zone. Beneath the frontal fold, there is a widespread occurrence of BSRs, suggesting the highly probable existence of substantial quantities of gas hydrates. A seismic flat spot and a few push-down reflectors below BSR are found lying beneath the anticlinal axis with bathymetric four-way dip closure. The flat spot, cutting across a series of dipping reflections beneath BSR, may indicate the contact between free gas and its underlying formation water. The push-down reflectors beneath BSRs are interpreted to result from abundant free gas hosted beneath the gas hydrate stability zone. The multiple paleo-canyon infills seen along and beneath the frontal fold and above BSRs may provide thick porous sands to host gas hydrates in the frontal fold.
30 citations
TL;DR: In this article, the authors used the Horner plot method to obtain true formation temperatures from measured borehole temperatures, which are disturbed by drilling processes, and calculated sub-bottom temperatures using theoretical pressure/temperature phase boundary that marks the base of gas hydrate stability zone.
27 citations
TL;DR: In this article, the authors used 2D bathymetry, average seafloor temperatures and regional geothermal gradients measured by thermal probes, as constraints to construct 2D theoretical conductive temperature fields using finite element methods.
20 citations
TL;DR: A high-resolution 2-ky record of changes in sediment delivery to Dahu, a floodplain lake in northeastern Taiwan, that suggests changes in precipitation has been inferred from organic matter, pollen, and spores in a 12m sediment core and from the organic matter compositions of soil, catchment plants, and fluvial suspended sediment as discussed by the authors.
13 citations
TL;DR: Li-yu Tan sediment cores were used in this paper to provide valuable information of vegetation history, climate change, and agricultural activity, including charcoal production by humans near the lake, based on the appearance of large charcoal particles.
8 citations