High-resolution records of thermocline in the Okinawa Trough since about 10000 aBP

2001 ◽  
Vol 44 (3) ◽  
pp. 193-200 ◽  
Author(s):  
Jiliang Wang ◽  
Yoshiki Saito ◽  
Tadamichi Oba ◽  
Zhimin Jian ◽  
Pinxian Wang
Keyword(s):  
High Resolution ◽  
Okinawa Trough ◽  
The Okinawa Trough

High‐resolution detection of geologic boundaries from potential‐field anomalies: An enhanced analytic signal technique

Geophysics ◽  
1996 ◽  
Vol 61 (2) ◽  
pp. 373-386 ◽  
Author(s):  
Shu‐Kun Hsu ◽  
Jean‐Claude Sibuet ◽  
Chuen‐Tien Shyu
Keyword(s):  
High Resolution ◽  
Potential Field ◽  
Amplitude Ratio ◽  
Okinawa Trough ◽  
Vertical Gradient ◽  
Analytic Signal ◽  
Magnetic Data ◽  
The Okinawa Trough ◽  
Simple Estimation ◽  
The City

A high‐resolution technique is developed to image geologic boundaries such as contacts and faults. The outlines of the geologic boundaries can be determined by tracing the maximum amplitudes of an enhanced analytic signal composed of the nth‐order vertical derivative values of two horizontal gradients and one vertical gradient. The locations of the maximum amplitudes are independent of the ambient potential field. This technique is particularly suitable when interference effects are considerable and/or when both induced and remanent magnetizations are not negligible. The corresponding depth to each geologic boundary can be estimated from the amplitude ratio of the enhanced and the simple analytic signals, which provides a simple estimation Such a method has been applied to magnetic data acquired in the Ilan Plain of Taiwan located at the southwestern end of the Okinawa Trough. The quantitative analysis shows that the underlying geologic boundaries deepen southward and slightly eastward. The enlargement of the Ilan Plain in the direction of the Okinawa Trough and the existence of north‐northwest and west‐northwest trending faults near the city of Ilan reveal a discontinuity between the Okinawa Trough backarc extension and the compressional process in Taiwan.

Characteristics of hydrocarbons in hydrothermal products of the Clam hydrothermal field from the Okinawa trough

2021 ◽  
Vol 167 ◽  
pp. 112277
Author(s):  
Xin Huang ◽  
Chao Huang ◽  
Yali Qi ◽  
Xiaoyuan Wang ◽  
Hansheng Cao
Keyword(s):  
Okinawa Trough ◽  
Hydrothermal Field ◽  
The Okinawa Trough

Element enrichment and U-series isotopic characteristics of the hydrothermal sulfides at Jade site in the Okinawa Trough

2009 ◽  
Vol 52 (7) ◽  
pp. 913-924 ◽  
Author(s):  
ZhiGang Zeng ◽  
ShaoXiong Yu ◽  
XueBo Yin ◽  
XiaoYuan Wang ◽  
GuoLiang Zhang ◽  
...  
Keyword(s):  
Okinawa Trough ◽  
The Okinawa Trough ◽  
Element Enrichment ◽  
Hydrothermal Sulfides

EXPRESS: A Piecewise Model for In Situ Raman Measurement of the Chlorinity of Deep-Sea High-Temperature Hydrothermal Fluids

2021 ◽  
pp. 000370282199911
Author(s):  
meng ge ◽  
Lianfu Li ◽  
Xin Zhang ◽  
Zhendong Luan ◽  
Zengfeng Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Deep Sea ◽  
Okinawa Trough ◽  
Peak Position ◽  
Hydrothermal Fluids ◽  
Calibration Model ◽  
The Okinawa Trough ◽  
Temperature Ranges ◽  
Piecewise Model ◽  
C 50

The chlorinity of deep-sea hydrothermal fluids, representing one of the crucial deep-sea hydrothermal indicators, indicates the degree of deep phase separation of hydrothermal fluids and water/rock reactions. However, accurately measuring the chlorinity of high-temperature hydrothermal fluids is still a significant challenge. In this paper, a piecewise chlorinity model to measure the chlorinity of high-temperature hydrothermal fluids was developed based on the OH stretching band of water, exhibiting an accuracy of 96.20%. The peak position, peak area ratio and F value were selected to establish the chlorinity piecewise calibration model within the temperature ranges of 0-50°C, 50-200°C and 200-300°C. Compared with that of the chlorinity calibration model built based on a single parameter, the accuracy of this piecewise model increased by approximately 4.83-12.33%. This chlorinity calibration model was applied to determine the concentrations of Cl for high-temperature hydrothermal fluids in the Okinawa Trough hydrothermal field.

Volcanoes geological mapping and structural geology with UAS High Resolution Digital Terrain Model : the Kuei-Shan Tao case example (Eastern Taiwan).

2021 ◽  
Author(s):  
Benoit Deffontaines ◽  
Kuo-Jen Chang ◽  
Samuel Magalhaes ◽  
Gérardo Fortunato
Keyword(s):  
High Resolution ◽  
Okinawa Trough ◽  
Volcanic Rocks ◽  
Digital Terrain Model ◽  
Structural Features ◽  
Point Of View ◽  
Geological Mapping ◽  
Lava Flows ◽  
Aerial Photographs ◽  
Structural Scheme

<p>Volcanic areas in the World are often difficult to map especially in a structural point of view as (1) fault planes are generally covered and filled by more recent lava flows and (2) volcanic rocks have very few tectonic striations. Kuei-Shan Tao (11km from Ilan Plain – NE Taiwan) is a volcanic island, located at the soutwestern tip of the South Okinawa trough (SWOT). Two incompatible geological maps had been already published both lacking faults and structural features (Hsu, 1963 and Chiu et al., 2010). We propose herein not only to up-date the Kuei-Shan Tao geological map with our high resolution dataset, but also to create the Kuei-Shan Tao structural scheme in order to better understand its geological and tectonic history.</p><p>Consequently, we first acquired aerial photographs from our UAS survey and get our new UAS high resolution DTM (HR UAS-DTM hereafter) with a ground resolution <10cm processed through classical photogrammetric methods. Taking into account common sense geomorphic and structural interpretation and reasoning deduced form our HR UAS-DTM, and the outcropping lithologies situated all along the shoreline, we have up-dated the Kuei-Shan Tao geological mapping and its major structures. To conclude, the lithologies (andesitic lava flows and pyroclastic falls) and the new structural scheme lead us to propose a scenario for both the construction as well as the dismantling of Kuei-Shan Tao which are keys for both geology and geodynamics of the SWOT.</p>

Helium isotopes in volcanic rocks from the Okinawa Trough-impact of volatile recycling and crustal contamination

2016 ◽  
Vol 51 ◽  
pp. 376-386 ◽  
Author(s):  
Zenghui Yu ◽  
Shikui Zhai ◽  
Kun Guo ◽  
Yonghua Zhou ◽  
Tong Zong
Keyword(s):  
Okinawa Trough ◽  
Volcanic Rocks ◽  
Crustal Contamination ◽  
Helium Isotopes ◽  
The Okinawa Trough
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