Chen Horng-yue

Academia Sinica · Institute of Earth Sciences

Nearby faults interact through stress changes induced by fault slip and viscoelastic flow. The process is, however, often elusive and can be geometry-dependent and time-variant. Here, we combine geodetic and field observations to characterize the interaction of two head-to-head, conjugate faults in eastern Taiwan during the 2022 Chihshang earthquak...

Plain Language Summary On 27 July 2022, the Mw 7.0 Abra earthquake hit northwestern Luzon, the Philippines, killing 11 people, damaging more than 30,000 buildings, and causing US$34 million worth of damage. The earthquake occurred on a previously unrecognized deep fault with no observable surface ruptures. In this study, we collected coseismic disp...

Faults interact through stress changes induced by earthquakes and viscoelastic flow acting in the lithosphere, but the process can be geometry-dependent and temporally-variant. The Chihshang earthquake sequence in September 2022, eastern Taiwan offers an unprecedented opportunity to study the interaction of two head-to-head conjugate thrust faults...

Plain Language Summary The southern Ryukyu margin near Taiwan accommodates the relative plate motion and backarc rifting. This region has suffered from tsunamis and large earthquakes with magnitudes of about eight in the history, yet insufficient offshore data still hamper our ability to fully characterize fault slip behaviors. We demonstrate how a...

To better characterize the vertical movements and the deformation behaviors across the plate suture of an arc-continent collision, we conducted annual repeated measurements on two precise leveling routes in a length of 34 and 37 km, respectively, across the middle part of the Longitudinal Valley in eastern Taiwan in 2004-2018. The 14-year-long resu...

Long-term seafloor geodetic measurements are important for constraining submarine crustal deformation near plate boundaries. Here we present an integrated analysis of a decade of GNSS/acoustic data collected at a site 60 km to the east of northeast Taiwan near the axis of the Okinawa Trough back-arc basin. We obtained a time-series of horizontal an...

The paper presents an estimation of the Earth’s crustal motion from the continuous GPS data at 6 stations (MTEV, MLAY, DBIV, TGIV, SMAV and SLAV) in the Northwestern and at PHUT (Hanoi) station using GAMIT/GLOBK software. The absolute displacements of the Earth’s crust at 7 stations in the IGS14 frame are respectively: 34.10±0.71 mm/yr (DBIV), 34.3...

Applications of low-cost single-frequency continuous GPS receivers for monitoring volcano and landslide activities as well as to complement dual-frequency receivers have been demonstrated to produce stable and accurate positioning. In studies of crustal deformation, the relative distance between monitoring stations may vary from several kilometers...

Rock uplift on the Earth surface is a key observation for studies of tectonics and geodynamic processes. Geodetic measurements from Global Positioning System (GPS) and leveling are able to track vertical deformation over a wide range of spatial and temporal scale. Taiwan mountain belt is subject to a rapid uplift rate of 20 mm/yr as revealed by GPS...

We measured seafloor movement using a GNSS/Acoustic technique at the south of the rifting valley in the western end of the Okinawa Trough back-arc basin, 60 km east of northeastern corner of Taiwan. The horizontal position of the seafloor benchmark, measured eight times between July 2012 and May 2016, showed a south-eastward movement suggesting a b...

Groundwater is an important part of the precious water resources. As the fresh surface water resources become scarcer because of climate change, population growth, and industrial activities, more and more groundwater has been extracted to meet the demands of various water uses (e.g. municipal, industrial, and agricultural). Excessive groundwater ex...

The global positioning system (GPS) has become an effective tool for measuring the dynamics of engineering structures from their absolute displacements. Although dual-frequency GPS receivers are widely adopted for structural monitoring applications to guarantee coordinate accuracy of the order of a few centimetres, the associated cost is too high t...

We present precise deformation velocity maps for the two year period from September 2011 to July 2013 of the northern Taiwan area, Taipei, by using persistent scatterer interferometry (PSI) technique for processing 18 high resolution X-band synthetic aperture radar (SAR) images archived from COSMO-SkyMed (CSK) constellation. According to the result...

A total of 17 low-cost single-frequency L1 global positioning system (GPS) receivers with real-time internet transmission have been set up to intensify the pre-existing network of continuously operating reference stations (CORS) in southeastern Taiwan since 2008. The main objective of this study is to investigate the validity and uncertainty of the...

Seasonal movement of GPS stations is often attributed to hydrological loading and other environmental factors. For the first time we observe seasonal motion associated with slow-moving landslides. Eight of 26 continuous GPS (cGPS) sites in the Central Range of Taiwan show long-term landslide-induced motion at rates of ∼3–15 mm/yr, ∼20%–60% of their...

In the southernmost Longitudinal Valley (LV), Taiwan, we analyzed a dense UPS array composed of 10 continuous stations and 86 campaign-mode stations. By removing the effects of the four major earthquakes (one regional and three local) occurred during the 1992 - 2010 observation period, we derived a new horizontal velocity field in this area, which...

About half of the 8 cm/yr of oblique convergence across the active con-vergent plate boundaries of Taiwan occurs in eastern Taiwan, across the Longitudinal Valley. Significant shortening and left-lateral slip occurs across the Longitudinal Valley fault there, both as shallow fault creep and as seismogenic fault slip. The south-ernmost Longitudinal...

In order to provide a detailed vertical velocity field in southernmost Longitudinal Valley where shows a complex three-fault system at the plate suture between Philippine Sea plate and Eurasia, we conducted leveling and GPS measurements, compiled data from previous surveys and combined them into a single data set. We compiled precise leveling resul...

We derive a velocity field using GPS data between 1993 and 2007 in the Chiayi–Tainan area located in the deformation front of the Taiwan mountain belt. The crustal motion with respect to Penghu shows large velocities of about 33–44 mm/yr in the west-northwest to west directions in the Western Foothills and the velocities decrease westward to 0–5 mm...

The 35-km-long Chihshang Fault is a rapidly creeping thrust among the 180-km-long Longitudinal Valley Fault system - the plate suture between the converging Philippine and Eurasian plates in eastern Taiwan. We combined geological surface investigation, geodetic data, seismological information, and a rate-dependant friction model, to illustrate fric...

The March 04, 2010, Jiashian, Taiwan earthquake (Mw 6.4) ruptured an unknown fault at depth in southwestern Taiwan. The main shock initiated near the town of Liuquei at 23km depth and the rupture propagated westward. Measurements of coseismic displacements from Taiwan Continuous GPS Array indicate horizontal displacements of 5–27mm in the NW–SW dir...

To realize the plate motion of the Philippine Sea Plate (PSP) and the characteristics of crustal deformation in the plate boundary zone between the PSP and Eurasia Plate, three seafloor geodetic arrays using a combination of GPS kinematic positioning and acoustic ranging techniques have been established off eastern Taiwan since 2008. Each array is...

To realize the plate motion of the Philippine Sea Plate (PSP) and the characteristics of crustal deformation in the plate boundary zone between the PSP and Eurasia Plate, three seafloor geodetic arrays using a combination of GPS kinematic positioning and acoustic ranging techniques have been established off eastern Taiwan since 2008. Each array is...

We use GPS-derived surface velocities, seismicity, as well as estimates of earthquake focal mechanisms from the time period before the 1999 Chi-Chi earthquake to evaluate spatial variations of surface strain rate and crustal stress regime in the Taiwan plate boundary zone. We estimate strain rates with a new but simple approach that solves for surf...

The NNE-striking Longitudinal Valley Fault (LVF) in eastern Taiwan is an extremely active inverse fault, which is considered as a collision boundary between the Eurasian and the Philippine Sea plates. The fault segments of the LVF demonstrate different slip behaviors, especially in the southern segment of the LVF. The deformation is partitioned by...

The Chengkung earthquake with ML = 6.6 occurred in eastern Taiwan at 12:38 local time on December 10th 2003. Based on the main shock relocation and aftershock distribution, the Chengkung earthquake occurred along the previously recognized N20°E trending Chihshang fault. This event did not cause human loss, but significant cracks developed at the gr...

Since 2001, we have set up a dense geodetic network with 52 campaign-mode GPS sites and seven continuously recording GPS stations as well as six leveling routes in the Taitung area, Taiwan. Our aim was to better characterize near-fault crustal deformation of active faults at the plate suture of the Philippine Sea plate and Eurasia in southeastern T...

We use GPS-derived coseismic and postseismic displacements of the 2003 Mw 6.8 Chengkung, Taiwan, earthquake to examine seismogenic behaviour of the southern Longitudinal Valley. We invert for fault slip on the Chihshang fault, a segment of the Longitudinal Valley fault, based on a simplified layered earth model and a listric-shape fault geometry. O...

Two successive large earthquakes (M(L) = 6.96 and 6.99) occurred in southern Taiwan offshore of the Hengchun town, Pingtung county, with the two main shocks separated by ail interval of only 8 minutes. Based on a dense network of continuously recording GPS stations (CORS) in Taiwan and adopting two different post-processing methods, we estimate the...

SUMMARYA moderate earthquake of Mw= 6.8 occurred on 2003 December 10. It ruptured the Chihshang Fault in eastern Taiwan which is the most active segment of the Longitudinal fault as a plate suture fault between the Luzon arc of the Philippine Sea plate and the Eurasian plate. The largest coseismic displacements were 13 cm (horizontal) and 26 cm (ve...

The M W 6.5 Chengkung earthquake occurred at 04:38 UTC on 10 December 2003. Thirty continuously recording GPS stations (CORS) have been set up at different geological sites and distributed throughout a 140 km by 140 km area in southern Taiwan beginning in 2000. The GPS data is recorded daily for the CORS in 30 seconds sampling rate. The GPS data is...

On the basis of field observations and geodetic measurements we analyzed coseismic and postseismic deformation of the 2003, Mw = 6.5, Chengkung earthquake across the rupture trace of the Chihshang fault, which lies along the suture zone between the Philippine Sea plate and the Eurasian plate in eastern Taiwan. At three of our investigation sites al...

The MW 6.5 Chengkung earthquake occurred in eastern Taiwan at 04:38 UTC on 10 December 2003. The GPS data from eighteen continuously recording stations (CORS) and 86 campaign-surveyed stations (CSS) collected 18 days to 9 months before and 6 days to 4 months after the main shock are utilized to analyze the coseismic and postseismic deformation asso...

Precise, long-range GPS kinematic positioning to centimeter accuracy requires that carrier phase ambiguities be resolved correctly during an initialization period, and subsequently to recover the “lost" ambiguities in the event of a cycle slip. Furthermore, to maximize navigational efficiency, ambiguity resolution and carrier phase-based positionin...

ABSTRACT Institute of Earth Sciences, Academia Sinica, Taiwan, ROC * Corresponding author address:Dr. Horng-Yue Chen, Institute of Earth Sciences, Academia Sinica, Taiwan, ROC; E-mail: chenhy@earth.sinica.edu.tw On31 March 2002, a ML= 6.8 earthquake (called the “331 earthquake”) occurred in northeastern Taiwan off Hualien. The shock lasted over 30...

Theories and computer programs are developed for single- and multiepoch analyses of a global positioning system (GPS) baseline network using the datum-free and weighted constraint solutions. Single-epoch analysis is for evaluating data quality, removing outliers, examining network precision, and estimating coordinates. Multiepoch analysis is for si...

Permanent GPS networks have been established since the 1980s to support a variety of geodetic applications, ranging from local deformation monitoring to large scale crustal motion measurement. Continuously operating GPS (CGPS) networks, consisting of geodetic-grade, dual-frequency receiver systems, generally support relative positioning to sub-cent...

There is a trend for the establishment of regional-scale GPS permanent receiver networks, for a variety of applications including to support high accuracy, carrier phase-based positioning for surveying and precise navigation. When implemented in real-time, GPS users located within the region enclosed by multiple GPS reference stations can precisely...

In the 15-month period (September 1999 to December 2000) after the 1999 Chi-Chi, Taiwan, earthquake (Mw 7.6) about 80 campaign-surveyed GPS stations in central Taiwan were occupied up to seven times. Furthermore, seven continuous GPS stations were put into operation in the epicentral region mostly within three weeks after the main shock. GPS data f...

We use a Global Positioning System (GPS)-derived surface velocity field of Taiwan for the time period between 1993 and 1999 to infer interseismic slip rates on subsurface faults. We adopt a composite elastic half-space dislocation model constrained by the observed horizontal velocities projected into the direction of plate motion (306°). The GPS da...

We utilize Quasi Ionosphere-Free (QIF) post-processing algorithm to account for ionosphere delay and use addition parameters to solve for tropospheric bias. Then the estimated integer ambiguities and troposphere parameters are fixed to acquire kinematic relative positions at every epoch. Using kinematic relative positioning, data from the Taiwan co...

Continuously operating GPS networks have been used for many years to address two types of positioning applications. The first, perhaps best known application, is in relation to geodetic objectives such as the determination of crustal motion on a variety of spatial scales — from the measurement of the broad kinematics of tectonic plates to deformati...

Ti-Chih, v. 21, n. 2, p. 31-52, 2002

In the case of monitoring the crustal deformation due to active seismic fault or volcanic activity or subsidence due to underground mining, sub-kilometre resolution may be required. Therefore, the spatial resolution requirements cannot be economically satisfied using the current GPS techniques alone. Two solutions to the monitoring of highly dense...

In recent years space geodetic techniques such as the Global Positioning System (GPS), Very Long Baseline Interferometry (VLBI), and Satellite Laser Ranging (SLR) have been collocated to address many applications in geoscience. While results from all these techniques are contaminated by various biases and errors, a commonmode signal has been found...

Researchers from The University of New South Wales (UNSW), Australia, and from the Geographical Survey Institute (GSI), Japan, have commenced a joint project to develop, deploy and test an innovative hardware/software system design for an automatic, continuously-operated ground deformation monitoring system based on low-cost GPS receiver technology...

The standard scenario for GPS surveying is to use two carrier phase-tracking GPS receivers, one located at a "reference" station with known coordinates and the second one at a station whose coordinates are to be determined. (It is also possible to determine a trajectory when the second receiver is in motion.) However, the cost of two GPS receivers,...

this paper, the linear data combination algorithm that has been used is described, and the issue of "ambiguity recovery" techniques for data correction generation purposes is addressed. Three strategies are suggested: (1) using an "ambiguity recovery" technique if the data gap is shorter than a minute or so; (2) re-determining the integer ambiguiti...

 An adaptive finite-duration impulse response filter, based on a least-mean-square algorithm, has been used to mitigate multipath effects, and to derive tectonic and fault movement signals from continuous global positioning system (CGPS) data. By applying the filter on both pseudo-range and carrier-phase multipath sequences from CGPS observations o...

The 1990-1997 annually surveyed GPS data from 36 stations and continuous data from 3 permanent stations in southwestern Taiwan are utilized to study the spatial and temporal variations of crustal strain in the area. Moderate to remarkable contraction rates of 0.48-2.01 μ strain/yr in 91°-135° are observed in the vicinity of the Chukou fault (CKF)....

The 131 stations of the ‘Taiwan GPS Network’ were surveyed 4–6 times from 1990 to 1995 with dual-frequency geodetic receivers. The standard deviation of an observed baseline length with its linear trend removed is in the range of 6–10 mm for a 3–120 km long baseline. The average rates of length change for all baselines of the network and those from...

A 788 station 270 km wide Global Positioning System (GPS) network which spans the arc-continent collision zone in southern Taiwan has been surveyed 5 times from 1990 PP 1994 with dual-frequency geodetic GPS re-ceivers. The observed data are processed with Bernese softwa Qù, v.3.4, using the available precise ephemerides. The unknown residual tropos...

SUMMARY We use GPS-derived coseismic and postseismic displacements of the 2003M w 6.8 Chengkung, Taiwan, earthquake to examine seismogenic behaviour of the southern Longitudinal Valley. We invert for fault slip on the Chihshang fault, a segment of the Longitudinal Valley fault, based on a simplified layered earth model and a listric-shape fault geo...