碩士 / 國立臺灣大學 / 海洋研究所 / 99 / Chaochou fault is one of the most important tectonic lines in southern Taiwan, it’s almost north-south direction and about 85 Km. Generally believed that it is a thrust fault with left section strike-slip, but many scholars in recent studies have pointed out that Chaochou fault’s activity has been gradually lowered, even has not the signs of event. Until the 2006 Hengchun earthquake and the 2010 Jiasian earthquake, Chaochou fault began to be widely discussed. This study area is the part be covered by sediments between the location of Chaochou fault out of the land and the head of Fangliao canyon, we all know that the fault will not only build on land, but there have rarely cases to research the situation of the fault into the sea, so the purpose would like to know how the Chaochou fault develops after it gets into the sea, and it is related to the adjacent canyon, Fangliao, or not.
In order to do better research, we use multi-beam sonar to collect bathymetric data, trying to make high resolution topographic map, to do more accurate, more subtle terrain judge; And use side scan sonar system to do the inspection of the feature image, combined with underwater camera to make the video to provide more direct evidence; Finally, we used three source of seismic which is different from frequency and penetration to ensure that all forms of stratigraphic information can be comprehensive collection.
Base on topographic data, there have two distinct features can be seen, one is the survey area close to land have found that the phenomenon of topographic uplift, and the second is that there have at least two breaks near the head of canyon point to the land. The image of side scan sonar at the uplift region also revealed many special reflected signals caused by different density of water masses, taking underwater camera in the area, there have recorded some hole on the seabed and we suspect that there are the pipes for eruption. Final is the data of seismic, through the stratigraphic section that, on the seabed of the same sediment sources, the density of stratum at the central is large than both side, the hardness is also like that, so the central region has poor penetration, also the place can see some bundles of eruption over the seabed. In addition, the uplift of the strata below the seabed is along with bending, rather than the general level of accumulation of sedimentary environment, if we look closer, we can see the presence of curved strata has many discontinuities, but also the ruptures are from the deep began to develop.
We speculate by these clues, Chaochou fault is related with Fangliao canyon, if we do an imaginary line to connect these two structures, the line will pass through the uplift area. When combined with tectonic stress in southwestern Taiwan, it can be as a structure with left stress, and then there will form a positive flower structure on the corner by a compressive stress, a series of parallel rupture produce around there. The bulge region is generated by squeezing, let the strata dehydrated, make the density becomes large, and it’s the reason of the poor penetration. In this way, we can solve all sorts of phenomena and complete a seasonable connection.
| Identifer | oai:union.ndltd.org:TW/099NTU05279009 |
| Date | January 2011 |
| Creators | Tzu-Hsuan Chiu, 邱子軒 |
| Contributors | 宋國士 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 106 |
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