Author
Chii-Wen Lin
Bio: Chii-Wen Lin is an academic researcher from Central Geological Survey, MOEA. The author has contributed to research in topics: Fault (geology) & Fault scarp. The author has an hindex of 4, co-authored 6 publications receiving 88 citations.
Topics: Fault (geology), Fault scarp, Thrust fault, Paleoseismology, Holocene
Papers
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TL;DR: Based on core-boring estimates, the vertical displace- ment on both sides is 7 m along a 24 east-dipping thrust fault, which ruptured during the Chichi earthquake.
Abstract: The geomorphic expression of the frontal Western Foothills in central Taiwan is usually defined by a late Holocene scarp that ranges from tens to hundreds of meters in height. This scarp is the product of displacement on a near-surface 20- 30 east-dipping thrust fault, the Chelungpu fault, which ruptured during the Chichi earthquake. The large scarp height may correspond directly to the accumulation of successive surface ruptures. The Chushan site is located on the southern part of this fault where the Chichi earthquake produced a scarp with a 1.7-m vertical offset for the total vertical separation. Based on core-boring estimates, the vertical displace- ment on both sides is 7 m along a 24 east-dipping thrust fault. The results from our paleoseismic analysis indicate that five large paleoearthquake events have caused the large offsets during the past 2 ka. The radiocarbon age constraints of the paleoearth- quakes suggest a clustering of 540-790 cal yr B.P. (E2), 710-950 cal yr B.P. (E3), 1380-1700 cal yr B.P. (E4), 1710-1930 cal yr B.P. (E5), and the 1999 Chichi earth- quake. Events E3 and E4 have not been reported in previous studies and we did not observe event E1 (300-430 cal yr B.P.) at the site. Based on displacement and fault segmentation from the geologic features, we argue that the two new events may have occurred along the northern part of the Chelungpu fault. The vertical slip rate is estimated to be at least 3.9 0.2 mm/yr over the past 2 ka, which is similar to the long-term estimation through a calculation of late Pleistocene-Holocene terrace el- evations on the hanging wall.
43 citations
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TL;DR: In this paper, the authors showed that the Juisui fault of the Longitudinal valley fault is the most important arc-continent collisional boundary fault between the Philippine Sea plate and the Eurasian continent.
22 citations
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TL;DR: Based on stratigraphic ordering and a statistical comparison of radiocarbon dates using the OxCal program, Wang et al. as mentioned in this paper estimate that two pre-1951 earthquake surface ruptures at the Dafu site occurred in the periods A.D. 1736-1898 and A. D. 1564-1680.
Abstract: Paleoseismic trench excavations in the Dafu area of eastern Taiwan have provided data on the rupture history of the Rueisuei segment of the Longitudinal Valley fault during the late Holocene. The 1951 Taitung earthquake ruptured the Dafu site, which is characterized by several terrace raises with late Holocene sediments uplifted by the westward thrust fault. Trenches across the northwest-facing fault scarp exposed fluvial and alluvial deposit sediments. Although nearly all of the 23 radiocarbon ages vary somewhat within each layer, the overall age determined for each layer is in good accord with the stratigraphic ordering of these layers. Based on stratigraphic ordering and a statistical comparison of radiocarbon dates using the OxCal program, we estimate that two pre-1951 earthquake surface ruptures at the Dafu site occurred in the periods A.D. 1736–1898 and A.D. 1564–1680. The same OxCal model constrains the past two recurrence intervals to about 165 and 140 yr, although with sizable uncertainties, 55–215 and 90–260 yr, respectively, which are 95% ranges. Through the correlation of three trenches across the Longitudinal Valley fault, we are able to identify evidence for at least three earthquakes with moment magnitudes of about 7.0–7.2 that occurred up to 390 yr prior to and during 1951. Furthermore, based on the radiocarbon dates, the mean recurrence interval is roughly 150 yr (uncertainty is indeterminate), with a minimum vertical uplift rate of 8.5–12.2 mm/yr.
15 citations
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TL;DR: In this article, a blind thrust may exist between the plain (PL), the tilted tableland (TT), and the low hills (LH), based on geomorphology, drainage pattern and stratigraphic records.
10 citations
01 Jan 2007
TL;DR: Based on core-boring estimates, the vertical displace- ment on both sides is 7 m along a 24 east-dipping thrust fault, which ruptured during the Chichi earthquake as discussed by the authors.
Abstract: The geomorphic expression of the frontal Western Foothills in central Taiwan is usually defined by a late Holocene scarp that ranges from tens to hundreds of meters in height. This scarp is the product of displacement on a near-surface 20- 30 east-dipping thrust fault, the Chelungpu fault, which ruptured during the Chichi earthquake. The large scarp height may correspond directly to the accumulation of successive surface ruptures. The Chushan site is located on the southern part of this fault where the Chichi earthquake produced a scarp with a 1.7-m vertical offset for the total vertical separation. Based on core-boring estimates, the vertical displace- ment on both sides is 7 m along a 24 east-dipping thrust fault. The results from our paleoseismic analysis indicate that five large paleoearthquake events have caused the large offsets during the past 2 ka. The radiocarbon age constraints of the paleoearth- quakes suggest a clustering of 540-790 cal yr B.P. (E2), 710-950 cal yr B.P. (E3), 1380-1700 cal yr B.P. (E4), 1710-1930 cal yr B.P. (E5), and the 1999 Chichi earth- quake. Events E3 and E4 have not been reported in previous studies and we did not observe event E1 (300-430 cal yr B.P.) at the site. Based on displacement and fault segmentation from the geologic features, we argue that the two new events may have occurred along the northern part of the Chelungpu fault. The vertical slip rate is estimated to be at least 3.9 0.2 mm/yr over the past 2 ka, which is similar to the long-term estimation through a calculation of late Pleistocene-Holocene terrace el- evations on the hanging wall.
8 citations
Cited by
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TL;DR: The radiocarbon calibration program OxCal (4.0.3 and above) as discussed by the authors provides paleoseismologists with a straightforward but rigorous means of estimating these event ages and their uncertainties.
Abstract: Ages of paleoearthquakes (events), i.e., evidence of earthquakes inferred from the geologic record, provide a critical constraint on estimation of the seismic hazard posed by an active fault. The radiocarbon calibration program OxCal (4.0.3 and above; Bronk Ramsey 2007, 2001) provides paleoseismologists with a straightforward but rigorous means of estimating these event ages and their uncertainties. Although initially developed for the chronologic modeling of archaeological data from diverse sources ( e.g. , radiocarbon, historical knowledge, etc.), OxCal is readily adaptable to other disciplines requiring chronological modeling, such as paleoseismology (Fumal et al. 2002; Lindvall et al. 2002; Kelson et al. 2006; Noriega et al. 2006; Lienkaemper and Williams 2007; Yen et al. 2008).
OxCal employs Bayesian statistics as a means of incorporating all available chronological constraints. When radiocarbon ages are calibrated to calendar ages, the results can be expressed as probability distributions, which are often irregular and multimodal as shown in Figure 1. These distributions can be tightened by including additional chronological information. Stratigraphic order, the timing of the most recent event, and historical constraints are inputs to the model. Applying the stratigraphic order as a constraint is particularly powerful where calibrated age distributions overlap, in which case the modeling calculations reweight the distributions to reflect the knowledge that overlying layers must be younger.
This paper is intended as a primer for paleoseismologists or those modeling paleoseismic data. The current version of OxCal contains an option for additional output that is useful for seismic hazard modeling, such as mean and median values of age for paleoearthquakes (events); mean recurrence interval; and probability density functions for a variety of variables, including earthquake age, interval between events, and the average of all intervals. The standard deviation of the last quantity models the uncertainty …
133 citations
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TL;DR: In this article, the present-day and geologic vertical displacement field in the active Taiwan orogenic belt was characterized using GPS vertical velocities and precise leveling and 199 continuous GPS measurements from 2000 to 2008.
Abstract: [1] To characterize the present-day vertical displacement field in the active Taiwan orogenic belt, 1843 precise leveling and 199 continuous GPS measurements from 2000 to 2008 are collected and analyzed in this study. Vertical velocities derived from the leveling data are placed in a reference frame of the Chinese continental margin using continuous GPS observations at nearby sites. The leveling and GPS vertical velocities generally reveal a dome-shaped pattern with uplift of ∼0.2–18.5 mm/yr in the interior of the mountain range and subsidence on the flanks of the mountains and coastal plains. Modern uplift rates in the active fold and thrust belt are generally consistent with geologic uplift rates. However, present-day uplift rates in the Central Range are faster than the million-years-averaged exhumation rates. The modern subsidence rates are generally consistent with geologic rates, except for the rates in western coastal areas due to groundwater pumping. Present-day subsidence in the southern Central Range and northern Coastal Range is, however, inconsistent with long-term uplift, which may reflect interseismic elastic strain accumulation across faults. Present-day subsidence in northern Taiwan occurs in a region of postcollisional orogenic collapse. We model the present-day and geologic vertical velocities and published GPS horizontal velocity data across southern Taiwan using a 2-D lithospheric model. The model suggests a combined slip rate of 40 mm/yr on the frontal thrusts and 45 mm/yr on the Longitudinal Valley fault. The model requires an additional source of crustal thickening under the Central Range to match the observed present-day uplift rates.
122 citations
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TL;DR: The Taiwan Earthquake Model (TEM) project, supported by the Ministry of Sciences and Technology, evaluates earthquake hazard, risk, and related social and economic impact models for Taiwan through multidisciplinary collaboration.
Abstract: Taiwan is located at an active plate boundary and prone to earthquake hazards. To evaluate the island's seismic risk, the Taiwan Earthquake Model (TEM) project, supported by the Ministry of Sciences and Technology, evaluates earthquake hazard, risk, and related social and economic impact models for Taiwan through multidisciplinary collaboration. One of the major tasks of TEM is to construct a complete and updated seismogenic structure database for Taiwan to assess future seismic hazards. Toward this end, we have combined information from pre-existing databases and data obtained from new analyses to build an updated and digitized three-dimensional seismogenic structure map for Taiwan. Thirty-eight on-land active seismogenic structures are identified. For detailed information of individual structures such as their long-term slip rates and potential recurrence intervals, we collected data from existing publications, as well as calculated from results of our own field surveys and investigations. We hope this updated database would become a significant constraint for seismic hazard assessment calculations in Taiwan, and would provide important information for engineers and hazard mitigation agencies.
72 citations
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TL;DR: In this article, the authors used finite element models including a thrust fault embedded in a rheologically layered lithosphere to investigate its slip evolution during glacial loading and subsequent postglacial unloading.
68 citations
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TL;DR: In this article, it was shown via amechanical model that erosion also significantly influences the stress loading of thrust faults at the timescale of a seismic cycle and that erosion rates of about B0.1-20mmyr1, as documented in Taiwan and in other active compressional orogens, can raise the Coulombstress by B 0.1 -10 bar on nearby thrust faults over the inter-seismic phase.
Abstract: Assessing seismic hazards remains one of the most challenging scientific issues in Earthsciences. Deep tectonic processes are classically considered as the only persistentmechanism driving the stress loading of active faults over a seismic cycle. Here we show via amechanical model that erosion also significantly influences the stress loading of thrust faultsat the timescale of a seismic cycle. Indeed, erosion rates of about B0.1–20mmyr1, asdocumented in Taiwan and in other active compressional orogens, can raise the Coulombstress by B0.1–10 bar on the nearby thrust faults over the inter-seismic phase. Masstransfers induced by surface processes in general, during continuous or short-lived andintense events, represent a prominent mechanism for inter-seismic stress loading offaults near the surface. Such stresses are probably sufficient to trigger shallow seismicity orpromote the rupture of deep continental earthquakes up to the surface.
68 citations