DSpace collection: 期刊論文

Tide-modulated gas emissions and tremors off SW Taiwan

Thu, 23 Apr 2026 07:02:54 GMT

title: Tide-modulated gas emissions and tremors off SW Taiwan abstract: 摘要： The continental margin off SW Taiwan is in an incipient stage of orogeny and contains numerous active mud diapirs and mud volcanoes. Gas emissions out of the seabed off SW Taiwan are revealed by acoustic images from 38kHz echo sounders or sub-bottom profilers. However, the mechanism for gas emissions is still poorly understood. In this study, we show that the gas emissions out of the seabed and the associated tremors off SW Taiwan are strongly correlated with the ocean tides, especially with the diurnal and semidiurnal constituents. Particularly, for each tidal day the strong gas emissions (expulsions) and long-duration tremors occur mainly during both the rising periods to the higher high tides and the falling periods to the lower low tides. Both the gas emissions and tremor activities are generally quiescent near the tidal datum. On average, the daily intensity of gas emissions and the magnitude of tremors are positively proportional to the daily tidal range; a larger slope site implies a greater concentration of gas in the shallow sediments. Most of the individual tremors and long-duration tremors observed off SW Taiwan occur as results of the strong gas expulsions out of the gas-bearing seabed. The high-frequency components of the induced tremors quickly decay and are followed by horizontal low-frequency (~7Hz) harmonic oscillations of the seabed. Long-duration tremors may enhance seafloor instability and increase the potential for submarine landslides. •Gas emissions out of the seabed are modulated by the ocean tides.•Gas-induced tremors occur as results of gas expulsions out of seabed.•Average amplitude of daily tremors is proportional to daily tidal range.•The seabed off SW Taiwan generally oscillates horizontally around 7Hz. 出版者： Elsevier B.V 出版日期： 2013-05 出處： Earth and planetary science letters, 2013-05, Vol.369-370, p.98-107 資源來源： Elsevier ScienceDirect Journals Complete 版權： 2013 Elsevier B.V. 識別號： ISSN: 0012-821X 識別號： EISSN: 1385-013X 識別號： DOI: 10.1016/j.epsl.2013.03.013

Serpentinization of the fore-arc mantle along the Taiwan arc-continent collision of the northern Manila subduction zone inferred from gravity modeling

Thu, 23 Apr 2026 07:02:50 GMT

title: Serpentinization of the fore-arc mantle along the Taiwan arc-continent collision of the northern Manila subduction zone inferred from gravity modeling abstract: 摘要： Serpentinized peridotite in the fore-arc has been observed in a number of subduction zones, including the northern Manila subduction zone which terminates northward in the Taiwan arc-continent collision. How this zone of serpentinization changes northward from the subduction of thinned continental lithosphere to full arc-continent collision in the Taiwan orogeny is not well known. In this paper we present 2-D gravity modeling along three P-wave (Vp) transects across the Taiwan orogeny. Two of these transects were collected with ocean-bottom seismometers. These two transects provide good constraints on the velocity structure to the west of, and on land, southern Taiwan. Conversion of Vp to density in this area allows us to model the gravity anomaly with very little misfit. Along the subduction zone, however, the velocity models are poorly constrained in the upper mantle, where an anomalous density unit has to be used in order to model the short wavelength gravity anomaly in this area. A third transect across central Taiwan that is derived from the TAIGER local tomography data, provides good control on the crust and upper mantle Vp structure that we use to place provide density constraints for modeling the gravity anomaly in this part of the collision zone. In order to model the short wavelength gravity anomaly across the Longitudinal Valley and the southern Longitudinal trough, an anomalous density block is required beneath the fore-arc region. We interpret that the source of this anomalous density material could be serpentinized fore-arc mantle, similar to what is interpreted for the northern Manila subduction zone farther south. Water released from the subduction of the extended crust of the continental margin results in the serpentinization of the fore-arc area and may be driving the uplifting of the high-pressure rocks. •An anomalous density block observed in the fore-arc region.•The anomalous density block could be related serpentinization and distributes along the Longitudinal Valley, the suture zone.•The degree of serpentinization is approximately 18%. 出版者： Amsterdam: Elsevier B.V 出版日期： 2016-11-22 出處： Tectonophysics, 2016-11, Vol.691, p.282-289 資源來源： Elsevier ScienceDirect Journals 版權： 2016 Elsevier B.V. 版權： Copyright Elsevier BV Nov 22, 2016 識別號： ISSN: 0040-1951 識別號： EISSN: 1879-3266 識別號： DOI: 10.1016/j.tecto.2016.10.019

Possible northward extension of the Philippine Fault Zone offshore Luzon Island (Philippines)

Thu, 23 Apr 2026 07:02:44 GMT

title: Possible northward extension of the Philippine Fault Zone offshore Luzon Island (Philippines) abstract: 摘要： The Philippine Fault Zone, a system of left-lateral strike-slip faults traversing the length of the Philippine Islands, is associated with the oblique convergence between the Philippine Sea Plate (PSP) and the Eurasian Plate (EP). Although it is a major deformational structure within the diffuse PSP–EP convergent boundary, some of its segments, particularly its marine extensions, are not well studied. To investigate the crustal deformation in the marine prolongation of the Philippine Fault Zone offshore Luzon Island, multi-channel seismic (MCS) data, gravity data and centroid moment tensor solutions were used in this study. Focal mechanism solutions from the Global CMT catalog were inverted to determine the average principal stress directions and consequently understand the prevailing stress regime in the study area. The stress inversion results indicate that the direction of maximum compression (σ1) is 321°N, which coincides with the PSP–EP convergence direction. From the MCS profiles, the study area was subdivided into deformation zone and a relatively stable zone. Thrust faulting, folding and general uplift are observed in the deformation zone. This zone is further subdivided into the active and inactive segments. In the active segment, uplift is occurring in the submarine ridge. This deformation pattern can be related to the ongoing uplift in some regions bisected by the PFZ. The inactive segment, characterized by intense folding of the sequences and faulting of the basement and overlying sequences, is suggested as the precursor of the Philippine Fault Zone. Deformation appears to be recently shifted to the east as delineated by an uplifted N-NW trending submarine ridge offshore NW Luzon Island. 其他題名： Mar Geophys Res 出版者： Dordrecht: Springer Netherlands 出版日期： 2012-12 出處： Marine geophysical researches, 2012-12, Vol.33 (4), p.369-377 資源來源： TU - ZB Springer Deal Journals Übergangsvereinbarung 版權： Springer Science+Business Media Dordrecht 2013 版權： Springer Science+Business Media Dordrecht 2012 識別號： ISSN: 0025-3235 識別號： EISSN: 1573-0581 識別號： DOI: 10.1007/s11001-013-9169-5

Philippine island arc system tectonic features inferred from magnetic data analysis

Thu, 23 Apr 2026 07:02:27 GMT

title: Philippine island arc system tectonic features inferred from magnetic data analysis abstract: 摘要： Running along the middle of the Philippine archipelago from south to north, the Philippine fault zone is one of the world’s major strike-slip faults. Intense volcanism in the archipelago is attributed to the ongoing subduction along the trench systems surrounding it. This study interprets the magnetic data covering the Philippine fault zone and the bounding archipelago subduction systems to understand the structural characteristics of the study area. Magnetic data analysis suggests that the Philippine fault is roughly distributed along the boundary of high/low magnetization and separates the different amplitude features of the first order analytic signal. Visayas province is a specific area bounded by the other parts of the Philippine archipelago. Further differentiating the tectonic units, the proto-Southeast Bohol Trench should be the main tectonic boundary between Visayas and Mindanao. A clear NE - SW boundary separates Luzon from Visayas as shown by the variant depths to the top of the magnetic basement. This boundary could suggest the different tectonic characteristics of the two regions. 出版者： Taiwan: 中華民國地球科學學會出版日期： 2015-12-01 出處： TAO : Terrestrial, atmospheric, and oceanic sciences, 2015-12, Vol.26 (6), p.679-686 資源來源：華藝CEPS中文電子期刊服務版權： 2015. This work is licensed under https://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License. 識別號： ISSN: 1017-0839 識別號： ISSN: 2223-8964 識別號： ISSN: 2311-7680 識別號： EISSN: 2311-7680 識別號： DOI: 10.3319/TAO.2015.05.11.04(TC)