포항 지진의 진원 깊이 연구 = A Study of Hypocentral Depth of Pohang Earthquake

국문 초록 (Abstract)

2017년 11월 15일 포항지진(규모 5.4)은 깊이효과로 경주지진(규모 5.8) 보다 피해가 더 컸으나, 정확한 깊이가확증되지 않고 있다. 진원 깊이를 진원재결정을 통하여 역산한 결과, 대부분의 모델의 진원 깊이가 얕은 표층으로 도출된 반면, 지각구조가 가장 근접한 모델은 6.0 ~ 11.5 km 구간의 깊이로 산출되었다. 지온분석에서는 7.5 km 근방에서300oC의 온도가 관찰되어 지진유발층의 사례에 입각한 포항지진의 진원은 근접한 모델로 얻어진 7 km 근방인 것으로 추정되어진다.

다국어 초록 (Multilingual Abstract)

2017 Pohang earthquake (M 5.4) was more disastrous than 2016 Gyeongju earthquake (M 5.8), partly because of its shallow focal depth. However, precise focal depth of Pohang earthquake is still controversial. Close crustal model showed 6 ~ 11.5 km in relocation depth, whereas other models showed almost surface range. Geothermal study indicated temperature of 300oC at depth of 7.5 km. Related with observations of seismogenic layer, the focal depth of Pohang earthquake seems to be 7 km depth as obtained by close model

참고문헌 (Reference)

1 안해성, "한국 포항시 남구 해도동 일대에 분포하는 포항분지의 삼차원 지질 모델링" 대한지질학회 51 (51): 21-36, 2015

2 정태웅, "진원 깊이를 고려한 한반도 다중지연시간창 해석" 한국지구물리.물리탐사학회 16 (16): 293-299, 2013

3 정태웅, "경주 지진 여진의 진원 깊이 연구" 한국지구물리.물리탐사학회 20 (20): 49-55, 2017

4 Bonner, J. L., "Thermal constraints on earthquake depths in California" 93 : 2333-2354, 2003

5 Hirth, G., "The brittle-plastic transition in experimentally deformed quartz aggregates" 99 : 11731-11747, 1994

6 Scholz, C. H., "The brittle-plastic transition and the depth of seismic faulting" 77 : 319-328, 1988

7 Asep, N. R., "Separation of intrinsic and scattering attenuation using single event source in South Korea" 105 : 858-872, 2015

8 Cho, H.-M., "P and S-wave velocity model along crustal scale refraction and wide-angle reflection profile in the southern Korean peninsula" 582 : 84-100, 2013

9 Wadati, K., "On the travel time of earthquake waves (part II)" 7 : 101-111, 1933

10 Jackson, J. A., "Normal faulting in the upper continental crust: observations from regions of active extension" 11 : 15-32, 1989

11 Pace, B., "Layered Seismogenic Source Model and Probabilistic Seismic-Hazard" 96 : 107-132, 2006

12 Kim, H. J., "Heat flow in the Republic of Korea" 112 : B05413-, 2007

13 Liernert, B. R., "HYPOCENTER: An earthquake location method using centered, scaled, and adaptively least squares" 76 : 771-783, 1986

14 Lee, W. H. K., "HYPO71 (Revised): A computer program for determining hypocenter, magnitude, and first motion pattern of local earthquakes" U. S. Geological Survey 1-113, 1975

15 Kim, S., "Forward waveform modelling procedure for 1-D crustal velocity structure and its application to the southern Korean Peninsula" 185 : 453-468, 2011

16 Asep, N. R., "Depth dependent crustal scattering attenuation revealed by using single or few events in South Korea" 106 : 1499-1508, 2016

17 Mori, J., "Depth dependence of earthqake frequency-magnitude distributions in California: Implication for rupture initiation" 102 : 15081-15090, 1997

18 Cho, H.-M., "Crustal velocity structure across the southern Korean Peninsula from seismic refraction survey" 33 : L06307-, 2006

19 Chang, S.-J., "Crustal structure in southern Korea from joint analysis of regional broadband waveforms and travel times" 96 : 856-870, 2006

20 Sibson, R. H., "Continental fault structure and the shallow earthquake source" 140 : 741-767, 1983

21 Saikia, U., "Accurate location and focal mechanism of small earthquakes near Idukki Reservoir, Kerala: implication for earthquake genesis" 107 : 1885-1891, 2014