Cumulative offset analysis of the Central-Southern Yangsan Fault based on topography of Quaternary fluvial terrace

Kim, Namgwon; Choi, Jin‐Hyuck; Park, Seung-Ik; Lee, Tae Ho; Choi, Yeon-Seok

doi:10.14770/jgsk.2020.56.2.135

Cited by 15 publications

(6 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If so, the major kinematics of earthquake rupture could be explained by slip partitioning between the main strike-slip and subsidiary reverse-slip traces approximately 200 m apart at a very shallow depth (King et al, 2005). We note that right-lateral earthquakes were dominant along the southern part of the Yangsan Fault (Kim et al, 2020), and surface deformations on the detected fault section could be much more complex than in other sections of the Yangsan Fault. Therefore, we argue that the estimated vertical offset and its slip-rate might reflect only local variations, not represent the overall characteristics in the framework of the general structure of the Yangsan Fault.…”

Section: Fault Geometry and Kinematicsmentioning

confidence: 79%

“…In addition, we focused on faultrelated landforms such as knickpoints, deflected channels, shutter ridges, bulged alluvial fan surfaces, and offset river terraces. These geomorphic indicators have been used to recognize the trace of the Yangsan Fault (Cheon et al, 2020;Kim et al, 2020;Kim et al, 2021). Along with the potential fault traces, we carried out fieldwork to confirm whether they were faults or not.…”

Section: Fault Detectionmentioning

confidence: 99%

See 1 more Smart Citation

Detection of fault location and paleoseismic evidence in the cultural heritage site around Gyeongju, SE Korea

et al. 2023

View full text Add to dashboard Cite

Detecting faults and their paleoseismic parameters is important for understanding earthquake-fault behaviors and assessing earthquake hazards. We conducted a multidisciplinary investigation of the Yangsan Fault around Gyeongju, an old capital city in South Korea, one of the challenging regions for paleoseismic surveys due to the protection of cultural properties. Based on topographic analysis and field observations, we identified a 10-km-long fault trace in a north-south direction. We then investigated alluvial fans covering the fault to evaluate geologic evidence of paleoearthquakes based on airborne LiDAR-image, drilling core, and cosmogenic exposure age-and OSL age-dating. Our results showed that the alluvial fan at a minimum age of 63 ka was deformed by transpressional earthquakes during the Late Pleistocene. A total of ~2.5 m of vertical offsets were estimated by geomorphic restoration and stratigraphic correlations and were mostly accommodated on a western subsidiary fault. The distribution of exposure ages of the boulders on the deformed alluvial fans implied that horizontal offsets were accommodated by the main fault. These less-destructive approaches can play an essential role in cultural heritage protection zone and highly urbanized cities, where excavation is impossible.

show abstract

Section: Fault Geometry and Kinematicsmentioning

confidence: 79%

Section: Fault Detectionmentioning

confidence: 99%

Detection of fault location and paleoseismic evidence in the cultural heritage site around Gyeongju, SE Korea

et al. 2023

View full text Add to dashboard Cite

show abstract

“…However, it is difficult to identify field evidence for paleoseismicity owing to intense modification of the geomorphic expression of ruptures by surface processes (mostly erosion and deposition) and urbanization. Recently, Kim et al (2020) calculated the horizontal geomorphic offset (about 20-195 m) along the central SYF using river terraces through highresolution digital elevation models (DEMs) built from light detection and ranging (LiDAR) and aerial photography. However, slip-rate data for the entire fault during the Quaternary remain uncertain and contentious.…”

Section: The Yangsan Faultmentioning

confidence: 99%

“…Dextrally deflected and beheaded channels, as well as offset terraces, are identified along the fault trace (Figure 3a-c). These geomorphic offset markers have been cumulatively displaced up to a maximum of 130-160 m with a dextral sense of slip (Kim & Seong, 2021). We excavated an E-W-oriented trench (15 m long × 2 m wide × 2.5 m deep) across the lineament (Figure 3d).…”

Section: Ws Trenchmentioning

confidence: 99%

“…Recent morphotectonic studies, after acquisition of air-borne LiDAR data, have shown that the YF has undergone dominantly dextral slip with a minor reverse slip (e.g., Cheon et al, 2020;Kim et al, 2020;Song et al, 2020). A series of river terrace risers across the SYF are typical dextral slip markers (Kim et al, 2020), and the reverse slip corresponds closely to streamflow change in the Inbo area, including damming-up streams by the eastern block (Cheon et al, 2020). We argue that, however, earlier excavation surveys had tended to focus only the minor reverse component due to a limited 2D observations at trench walls.…”

Section: Stratigraphic Features Related To Fault Splay Kinematicsmentioning

confidence: 99%

See 1 more Smart Citation

Stratigraphic Constraints of Rupture Kinematics and Scenarios of Paleoearthquakes on the Southern Yangsan Fault, SE Korea

Kim

Choi

Cheon

et al. 2021

Preprint

View full text Add to dashboard Cite

After the 2016 Gyeongju Earthquake (M W 5.5) in SE Korea, the NNE-SSW-striking Yangsan Fault (YF) seismicity has emerged as a significant scientific issue and hazard. Despite previous studies of the seismicity of the YF, the paleoseismic information of the fault remain uncertain. We carried out paleoseismic investigations to characterize surface rupturing and the paleoseismic history of the northern section of the southern YF. Deflected streams and displaced river terraces indicate a dextral sense of slip, and fault splays cutting unconsolidated sedimentary strata in trench walls show an east-side-up geometry. The dextral strike-slip faulting with a minor reverse component is characterized by several noticeable stratigraphic features, including fissure-filling deposits, sag ponds, and cut-and-fill streams along the fault splay. Based on fault-sediment cross-cutting relationships and optically stimulated luminescence ages of unconsolidated sediments, we propose two possible rupture scenarios for the most recent earthquake event along the studied fault section during the Late Pleistocene: (1) a single rupture along the entire section (WS-MH-IBN-IB) at ca. 30 ka and (2) individual partial ruptures along two segments of the section (WS-MH and IBN-IB) during 33-30 and 29-17 ka, respectively. It is also noted that the timings of earlier ruptures (penultimate earthquake events) of the two segments are 37-35 and 70-52 ka, respectively. Furthermore, the timing(s) of the most recent earthquake for our studied section is much older than that of the southern section of the northern YF.

show abstract

New evidence of late Quaternary earthquake surface rupturing along the Gongju Fault, central Korea

Kim,

Choi

et al. 2024

Geosci J

View full text Add to dashboard Cite

Cumulative offset analysis of the Central-Southern Yangsan Fault based on topography of Quaternary fluvial terrace

Cited by 15 publications

References 46 publications

Detection of fault location and paleoseismic evidence in the cultural heritage site around Gyeongju, SE Korea

Detection of fault location and paleoseismic evidence in the cultural heritage site around Gyeongju, SE Korea

Stratigraphic Constraints of Rupture Kinematics and Scenarios of Paleoearthquakes on the Southern Yangsan Fault, SE Korea

New evidence of late Quaternary earthquake surface rupturing along the Gongju Fault, central Korea

Contact Info

Product

Resources

About