1) We have mapped two active faults, the Chishan Fault, striking NNE-SSW and the Kaoping River Fault with N-S trend in the southern Taiwan. Both faults are reverse faults, probably with high angle fault plane. Newly found geomorphic evidence for the i
orphologic expression of the Chishan Fault, oblique to the present shortening direction, is often rather poor, just
xpressed as lineament following the shattered zone. High-standing sandstone ridge f the Chungliao Mountains and several lineaments along the Chishan Fault are dentification as an active fault is the back-tilting of the terrace (lineament a-a’) for the Chishan Fault and east facing flexural scarps limiting the eastern boundary of T2 and T3 for Kaoping River Fault. No evidence for the strike-slip component for both faults is observed.
2) The Chishan fault, created in Miocene time, has longer history than the Kaoping River Fault. Since the present study area is under the E-W compression, N-S trending Kaoping River Fault, which has activated during the last ca. 100,000 years has a better geomorphic expression as prominent east facing flexural scarp.
3) Both faults are probably seismogenetic faults, but the exact amount of offset and slip rate during the late Quaternary are not determined.
4) The Chishan Fault may have multiple traces. M
e o
structural relief following the geologic structure related to the Chishan Fault.
Understanding structural relief and its distinction from the actual tectonic relief is one of the important problems in the area where presence of soft mudstone or alternation of sandstone and shale is predominated
References
ang, G.S., 2004. Deformation and occurrence of the Che-ling-pu
rthquake, Western Foothills, central Taiwan. Journal of Asian
)(Earthquake
n Geological map of Tainan
ai, K.Y., Chen, Y.G., Hung, J.H., Suppe, J., Yue, L.F. and Chen, Y.W., 2006. Surface deformation related to kink-folding above an active fault: Evidence from geomorphic features and co-seismic slips. Quaternary International, 147:
44-54.
in, A.T., 1991. Lithofacies and the sedimentary environment evolution of the Plio-Pleistocene Series in the southwestern Taiwan foothills region (in Chinese). M.S. Thesis, Natl. Taiwan Univ., Taipei: 93 pp.
in, C-W., Chang, H-C., Lu,S-T., Shih,T-S. and Hunag,W-J. 2000, Active Fault Map of
Taiwan with explanatory text. The second edition, Central Geological Survey ta,Y., Miyawaki, A. and Shiomi, M.,1992, Active faults on Sado Island, off central Japan and their implication on marine terrace deformation, Journal of
Geography, Japan (Chigaku-zasshi),101, 205-224 (in Japanese with English abstract)
ta, Y., Lin, Y.N., Chen,Y-G, Chang, H-C, and Hung,J-H. 2005, Newly found Tunglo Chang, J.C. and Y
Fault from geomorphic evidence. Quaternary International, 115-116: 177-188.
Chen, L., 2005. A study on occurrences and eruptive activities of mud-volcanoes along the Chishan Fault, Southwestern Taiwan (in Chinese with English abstract). M.S. Thesis, Natl. Kaohsiung Normal Univ., Kaohsiung: 119 pp.
Chen, W.S., Chen, Y.G., Shih, R.C., Liu, T.K., Huang, N.W., Lin, C.C., Sung, S.H. and Lee, K.J., 2003. Thrust-related river terrace development in relation to the 1999 Chi-Chi ea
Sciences, 21, 473-480.
Chen, W.S., Huang, N.W., Yang, C.C., Yu, N.T., Chou, F.H., Yen, I.C., Sung, S.H. and Yang, H.C., 2005. Strip map of Chishan and Longchuan Faults Central Geological Survey, Trenching and Past Earthquake Research (4/5
Geological Survey and Establishment of Archive of Active Fault): 48.
Corporation, C.P., 1989. Chinese Petroleum Corporatio (1:100,000).
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active fault system in the fold and thrust belt in northwestern Taiwan ced from deformed terraces and its tectonic significance.
Shih, T K.H., Shih, C.D., Yang, G.S. and Hsu, M.Y., 1984. A
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PhD Thesis, Natl. Taiwan Univ., Taipei: 212 pp.
Yu, S.B., Kuo, L.C. Punongbayan, R.S. and Ramos, E.G., 1999. GPS observation of dedu
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Shen, L.C., Hou, C.S., Hu, J.C., Chan, Y.C., Huang, C., Lai, T.C. and Lin, C.W., 2003.
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Shih, T.T., Chang, J.C., Teng, K.H., Shih, C.D., Yang, G.S. and Hsu, M.Y., 1983.
Active fault and landforms in Chaochou fault zone (in Chinese with English abstract). Geographical Studies, 7: 7-34.
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geomorphological study of active fault in western and southern Taiwan (in Chinese with English abstract). Geographical Research, 10: 49-94.
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the area from Chishan to Fengshan, southern Taiwan (in Chinese with English abstract). Spec. Publ. Cent. Geol. Surv., 6: 263-295.
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Yang, G.S., 1986.A geomorphological study of active faults in Taiwan—especially on the relation between active faults and geomorphic surfaces. PhD thesis, Department of Geography, Chinese Culture University, 178p ,
crustal deformation in the Taiwan-Luzon region. Geophys. Res. Lett., 26:
923-926.
國科會補助出席國際會議報告
會議中文名稱：美國地球物理聯合會2007秋季 會
議英文名稱：American Geophysical Union (AGU) 2007 Fall Meeting 年
AGU 2007 Fall Meeting Programs AGU 2007 Fall Meeting Abstracts光碟 部份與會人士發表之相關資料
、其他
會議舉辦時間：2007/1
會議舉行地點：Moscone Center, San Francisco, California, U. S. A.
加會議經過
此次會議時間由於鄰近美國耶誕假期，舊金山至台北直飛班機機票均已售 罊，因此取道洛杉磯轉機，增加了不少飛行時間。
metry Chi-Chi Earthquake
an
ces, National Taiwan Univ., Taiwan, R.O.C.
附錄：發表論文摘要(共計四篇)
Ground Displacements and Fault-plane Geo beneath: a case of 1999
(Mw 7.6) at Tsaotun in Central Taiw
Yu-Ting Kuo1, Mong-Han Huang1, Yue-Gau Chen1, Jean-Philippe Avouac2
1 Dept. of Geoscien
2 Division of Geological and Planetary Sciences, Caltech, California, U.S.A.
Abstract
Long-term ground deformation recorded in deformed geomorphic surfaces is
supposed to be the cumulative strain produced by associated active structure and certainly related to the subsurface structure geometry. Moreover, by time domain
the deformation also can be divided into components: co-, post-, and inter-seismic.
A case that may demonstrate the entire process is at Tsaotun in central Taiwan,
where widely developed geomorphic surfaces have long been noticed and surface ruptures of 1999 Taiwan Chi-Chi earthquake (Mw 7.6) ran though. Landform
investigation, geodetic work, sub-pixel comparison of aerial photos, and D-InSAR analysis are conducted to reconstruction the entire deformation process mentioned
abov
tion
rial photographs to obtain detailed horizontal displacement across the surface ult bends beneath greater and more rapid in
coseismic ground displacement cannot tirely match the long-term surface deformation recorded in the geomorphic surfaces.
owever, by the post-seismic ground displacements obtained from InSAR a few other e.
In our previous study, we have used sub-pixel correlation on high-resolu
ae
ruptures, which has revealed that the fa
the southern segment. Nevertheless, the en
H
active structures, such as secondary strike-slip faults, may play a role to e earthquake.
By available co- and post-seismic ground displacements, we successfully rebuild a
sur of
when, wh r. Our
result zation
plan for the
Give a scientific purpose in the title] Interseismic modeling in
Ray Y. Chuang1, M. Meghan Miller2, J. Bruce H. Shyu3, Yue-Gau Chen1
Road, Taipei, 10617, Taiwan
3Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität
The island of Taiwan lies at the junction of the Eurasian and Philippine Sea
long regarded as one of the major collisional suture zones, to the east and a fault-and-thrust belt to the west across the island. Based on recent published geolo
depth but locked at deeper part in the southern section. In western Taiwan, active accommodate the tentative stress accumulation in a larg
fault-plane model at Tsaotun. Using this model we can satisfactorily explain the
face deformation in different time domain. The model also describe the details ere, and how much the rate of the ground displacements would occu
is undoubtedly valuable to improve the building code and to assist urbani purpose of seismic hazard mitigation.
the Taiwan region
1Department of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt
2Department of Geological Sciences, Central Washington University, 400 E.
University Way, WA 98926, USA
Munich, Luisenstr. 37, 80333 München, Germany
plates. The convergence between two plates forms the Longitudinal Valley, which has been
gical map and relevant studies, several major active faults are currently acting in Taiwan.
In eastern Taiwan, the Longitudinal Valley fault, the most dominant fault within the suture zone, is locked at the northern section and is creeping at shallow
faults imbricate and propagate to the west above a major Taiwan detachment at
depth. Based on ?, most of the active thrust faults and tear faults in western Taiwan
the locking of the subduction zones along the Ryukyu and Manila Trenches constrain the interseismic deformation across the Taiwan region and accumulate
are locked. The locking and creeping of the active faults around Taiwan as well as
strain which may be released during future earthquakes.
analyze GPS data from 1990-1997 by what?. This time span excludes the effects of
block model across the Taiwan region to quantify kinematically consistent estimates
ibe the GPS velocities and locking The GPS constrained block model provides estimates of present-day fault slip
ial within the entire Taiwan region.
Implications of river morpholo hu fault in NW Vietnam
to active Dien Bien Phu fault, we use 1/50,000 topographic data AS
In order to characterize interseismic deformation around Taiwan region, we
large earthquakes in the century, especially the Chi-Chi earthquake. For better understanding interseismic coupling and fault slip, we construct a three-dimensional
of block motions and fault slip rates. The model combined elastic half-space and block motions based on the backslip model to descr
faults.
rates and seismic potent
gy response to Dien Bien P
Kuang-Yin Lai1, Yue-Gau Chen1, Doan Dinh Lam2
1 Institute of Geosciences, National Taiwan University, P.O. Box 13-318, Taipei 106, Taiwan
2 Institute of Geological Sciences, Vietnamese Academy of Science and Technology, Hanoi, Vietnam
Abstract
In northern Vietnam, most rivers are flowing southeastward sub- or parallel to the valley of Red River and characterized by long but narrow catchments. The Dien Bien Phu fault is associated with the most seismically active zone in Vietnam and situated in the potential eastern boundary of the rotating southeastern Tibetan block.
It cuts the Da River, the largest tributary of Red River in northwest Vietnam and has distorted the drainage basin resulting in complex river patterns. To assess the river
ogy response morphol
and TER images to map the precise river courses and digital elevation model data of SRTM to retrieve and analyze the river profiles. From the mapping results, the N-S striking fault results in three conspicuous north-trending river valleys coincided
with the different fault segments to facilitate the measurement and reconstruction of the offsets along the fault. Further combining the longitudinal profile analysis we obtain ca. 10 km offsets by deflected river as the largest left-lateral displacement recorded along the active fault. The restored results show the downstream paleochannel of the Da River had been abandoned and becomes two small tributaries in opposite flow directions at present due to differential crustal uplift. Also the
resent crisscross valley at the junction of the Da River and the fault is resulted from the ca
The implication of elevated lacustrine sediments in the middle reach of the Yarlung-Tsangpo and Nyang River,
e-Gau Chen1, Ling-Ho Chung1, in Lai1, Ray Y. Chuang1, Shujun Zhao2, Gongming Yin2 and Zhongquan Cao3 . tate Key Laboratory of Earthquake Dynamics, Institute of Geology, China
nteraction mechanisms among climate, crustal uplift and related erosion proc
p
pture by another river which has been also deflected by the neotectonics.
Based on our observations on river response, the Dien Bien Phu fault is a sinistral dominant fault with an uplift occurring in its eastern block. Furthermore the active Dien Bien Phu fault does not cut through the Red River northward indicating the western block of the fault can not be regarded as a single rigid block. There should be possible to find NW-SE trending faults paralleling to Red River to accommodate the deformation of the western block of the fault.
Tibet
Shao-Yi Huang1, Yu-Nung Lin1, Jingwei Liu2 ,Yu Kuang-Y
1. Department of Geosciences, National Taiwan University 2 S
Earthquake Administration
3. Seismological Bureau of Tibet Autonomous Region
The i
esses in the orogenic belt became one of the popular topics in the past decade, especially in the collisional margin of Eurasian Plate and Indian Plate where stands the most spectacular plateau in the world in terms of elevation and geomorphology.
We investigated the outcrops of lacustrine deposits in the lower terraces of the Nyang River and established the stratigraphic column for entire depositional sequence.
Woods and charcoals were collected for radiocarbon dating and sands for optical stimulated luminescence (OSL). Based on our observation, the alluvial and lacustrine environments occurred alternatively. Among them two well developed varve layers were identified in the sequence.
The occurrence of varve strata and moraine-related delta facies have raised subsequent questions such as did the breakout of the dammed lake strike this drainage repeatedly? What is the mechanism of the dammed lakes, were the paleolakes dammed by monsoon driven valley glacier or tectonic structures? And, the timing of the paleolakes will be crucial as well.
Based on the preliminary radiocarbon and OSL dates from the bottom and the top of the depositional succession, the paleolakes took place no younger than 20ka. The interbeded sand and silt recorded abundant ripple cross beds, parallel lamination, and syndepositional deformation, representing the transition of environments from delta front to beach ridges of the frontal floodplain. Two sections of varve layers indicate two gradational stages of the delta. This coarsening-upwards sequence recorded details of episodic changes of depositional environment from delta front to floodplain and the evolution of this moraine-related delta.
國科會補助出席國際會議報告
會議中文名稱：美國地球物理聯合會2007秋季年會
會議英文名稱：American Geophysical Union (AGU) 2007 Fall Meeting 會議舉辦時間：2007/12/10~2007/12/14
會議舉行地點：Moscone Center, San Francisco, California, U. S. A.
一、參加會議經過
本次會議共計發表論文海報共四篇，並於前一晚(12/09)深夜即抵達位於開 會地點附近的住宿旅館。
此次 AGU 2007 秋季年會排定五天的議程，包括 24 個領域，每個領域底下再 區分不同的主題。除了會議議程五天內上、下午的海報論文發表，由於各個領域 的議程再五天的會議中均有，因此主要參與每天 Tectonophysics 與 Seismology 這 兩個領域底下的主題，再加上其他領域與本人研究有關的主題。
二、與會心得
每年美國地球物理聯合會的秋季年會(AGU Fall Meeting)是地質學界的一大 盛事，主要發表海報論文。與去年相比，此次會議的規模又更形擴大，Moscone Center 的空間已嫌不足，部分議程與相關活動移至鄰近的其他場所舉行。
來到這裡以後，發現地質學界的變化也一日千里，以往模糊的影像與粗略的 圖片，現在不僅解析度提高許多，甚至可直接提供 3D 的影像，讓觀眾更能了解 作者想表達的內容，而地質學研究的範疇也已從上天下海，進而進入外太空研究 其他的行星(ex:火星)。另外，此次由一些觀眾特別踴躍的議程可以了解，現今的 地質學已不是解析出某地質事件就足夠，現在的研究必須把地質學中不同領域結 合起來做出綜合的結果，甚至做出整個動態改變的過程與模型。所謂坎井之蛙，
不知江海之大；參與國際大型會議以及與眾人討論，是了解世界最新發展所必須 的，如此才能擠身國際競爭的行列。
本人在此次年會中主要是擔任主持人，從世界各的的優秀學者所發表的演說 中，更可看出地球科學學門的日新月異，以及各國間的激烈競爭，因此我國乃有 必要更進一步加強在地球科學上的研究以及教學，始得跟得上國際腳步。
三、攜回資料名稱及內容
z AGU 2007 Fall Meeting Programs z AGU 2007 Fall Meeting Abstracts光碟 z 部份與會人士發表之相關資料
四、其他
此次會議時間由於鄰近美國耶誕假期，舊金山至台北直飛班機機票均已售 罊，因此取道洛杉磯轉機，增加了不少飛行時間。
附錄：發表論文摘要(共計四篇)
Ground Displacements and Fault-plane Geometry beneath: a case of 1999 Chi-Chi Earthquake (Mw
7.6) at Tsaotun in Central Taiwan
Yu-Ting Kuo1, Mong-Han Huang1, Yue-Gau Chen1, Jean-Philippe Avouac2
1 Dept. of Geosciences, National Taiwan Univ., Taiwan, R.O.C.
2 Division of Geological and Planetary Sciences, Caltech, California, U.S.A.
Abstract
Long-term ground deformation recorded in deformed geomorphic surfaces is supposed to be the cumulative strain produced by associated active structure and certainly related to the subsurface structure geometry. Moreover, by time domain the deformation also can be divided into components: co-, post-, and inter-seismic. A
Long-term ground deformation recorded in deformed geomorphic surfaces is supposed to be the cumulative strain produced by associated active structure and certainly related to the subsurface structure geometry. Moreover, by time domain the deformation also can be divided into components: co-, post-, and inter-seismic. A