Investigation of long-term and short-term seismicity in Vietnam

Nguyen, Hong Phuong; Nguyen, Ta Nam

doi:10.1007/s10950-019-09846-x

Cited by 8 publications

(7 citation statements)

References 31 publications

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“…Figures 2a-2b illustrate the focal mechanisms of two earthquakes recorded at Song Tranh 2 hydropower plant in 2015 obtained by using the moment tensor inversion method. The results show that the right-lateral strike-slip mechanism of the source faults is in the Northwest-southeast direction [7].…”

Section: Seismic Activitymentioning

confidence: 91%

“…Let t be the origin time of earthquake occurrence, h is a focal depth, M is the magnitude, i and j be the order numbers of these earthquakes in a catalog, and j > i. The second event can be considered as the aftershock of the first one if the following conditions are satisfied: the epicentral distance between the two events is less than a given value R(Mi), hjhi ≤ H(M); and Mj ≤ Mi, where T(M), R(M) and H(M) are empirical functions [7,22]. The algorithm of foreshock removal is similar.…”

Section: Earthquake Catalogmentioning

confidence: 99%

“…This is the basis for applying the model of [31] in calculating earthquake hazards for Da Nang city [31]. The ground motion attenuation model of [31] ] 𝑓𝑜𝑟𝑉 𝑆30 > 𝑉 𝑅𝐸𝐹 (7) where ln(Y) is the median spectral acceleration; ln(YREF) is the reference ground-motion model through the nonlinear site amplification function ln(S); Mw is moment magnitude; R is the source-to-site distance measure, (km), for which RJB, Repi, Rhyp are used for different models; FN and FR are the style-of-faulting dummy variables, that are unity for normal and reverse faults, respectively, and zero otherwise. The parameter c1 in the reference groundmotion model is the hinging magnitude and it is taken as Mw 6.75; σ is the total aleatory variability of the model, which is composed of within-event (φ) and between-event (τ) standard deviations (SDs); b1 and b2 are the period-dependent estimator's parameters of the nonlinear site function; c and n are the period-independent coefficients of the reference ground-motion model.…”

Section: Ground Motion Prediction Modelsmentioning

confidence: 99%

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Probabilistic seismic hazard assessment for Da Nang city, Vietnam

Phuong¹,

Quyen²,

Truyen³

et al. 2022

VNJHM

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This paper presents the probabilistic seismic hazard assessment (PSHA) results for Da Nang city. A regional earthquake catalog was updated until 2021 and comprehensive seismic source zones within 150 km of Da Nang city were used. The PSHA results for Da Nang city are presented in the form of probabilistic seismic hazard maps, depicting peak horizontal ground acceleration (PGA) with 10%, 5%, 2% and 0,5% probability of exceedance in 50 years, corresponding to return times of 475; 975; 2,475 and 9,975 years, respectively, as well as the 5-hertz (0.2 s period) and 1-hertz (1.0 s period) spectral accelerations (SA) maps with 5-percent damping on a uniform firm rock site condition, with 2% probability of exceedance in 50 years, corresponding to a 2,475 year return period. The results show that, for the whole territory of Da Nang city, for all four return periods, the predicted PGA values correspond to the intensity of VI to VIII degrees according to the MSK-64 scales. As for the SA maps, for the 2,475-year return period, the predicted SA values at 1.0 s period correspond to the intensity of VI, while the predicted SA values at 0.2 s period correspond to the intensity of VIII to IX according to the MSK-64 scales. These probabilistic seismic hazard maps present short-and long-term forecasts of seismic hazards for Danang city.

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Section: Seismic Activitymentioning

confidence: 91%

Section: Earthquake Catalogmentioning

confidence: 99%

Section: Ground Motion Prediction Modelsmentioning

confidence: 99%

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Probabilistic seismic hazard assessment for Da Nang city, Vietnam

Phuong¹,

Quyen²,

Truyen³

et al. 2022

VNJHM

View full text Add to dashboard Cite

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“…On 16 June 2020, a moderate-sized earthquake of local magnitude (M L ) 4.9 struck the Muong Te area, located in the northwestern part of Vietnam. According to the compiled seismicity catalog in the Vietnam region (Nguyen et al, 2019), this was one of the strongest earthquakes in the Muong Te block over 100 years ago. The main shock has caused some damage to infrastructure and public panic in the area near the source (Fig.…”

Section: Introductionmentioning

confidence: 99%

“…In the Muong Te block, the most notable fault in the region is the N-S trending Dien Bien Phu fault which is considered a boundary between the Simao and Indochina blocks. In addition, the Muong Te region comprises three other remarkable rank II faults, including the Upstream Da River fault, Muong Te fault, and Muong Nhe fault (Nguyen et al, 2019). Owing to the presence of these faults, a more completed earthquake catalog is needed to deepen the understanding of seismogenic fault zones in the Muong Te block and adjacent areas.…”

Section: Introductionmentioning

confidence: 99%

Automatic earthquake detection and phase picking in Muong Te, Lai Chau region: an application of machine learning in observational seismology in Vietnam

Cong

Van

Thi

et al. 2022

Vietnam J. Earth Sci.

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We applied the automatic detection and picking of P- and S-wave to one-year continuous raw seismic data from 17 seismic stations in the Muong Te area, northwestern Vietnam. The deep learning picker, Earthquake Transformer, has performed automatic picking of P- and S-waves, and phase association, then we located the earthquakes using Hypoinverse and NonLinLoc programs. The newly derived catalog consisted of 893 events, which is significantly higher than the number of events in the manual catalog. From this new catalog, we can observe more earthquakes related to the Muong Te ML 4.9 earthquake on June 16, 2020, and the earthquake activity in other faults such as the Dien Bien Phu and Muong Nhe faults. The extended catalog can further study the seismogenesis and the seismic velocity structure of the crust beneath northwestern Vietnam.

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