초록

○ 한반도 및 주변해역 미소지진 다발지역 규명
- 지리정보시스템 점밀도 분석을 이용한 한반도 계기지진 다발지역 규명
○ 경주지역 미소지진 탐지
- 지진재발 성향을 이용한 미소지진 탐지
○ 경주지역 미소지진 분석
- 미소지진 진원요소 정밀 결정
- 2014년 9월 23일 발생한 규모 3.6 경주지진 단층면해
○ 경주지역 피해유발 지진 발생 가능성
- 과거 소규모 지진 발생이력 및 최근 미소지진 발생현황을 이용한 지진유발가능 단층규명

Abstract ▼

IV. Results of the Study
It has been confirmed that many micro-earthquakes occur in the study area by applying waveform correlation detector to the continuously recorded earthquake data. Results of initial analysis indicate 729 earthquakes occurred and recorded by more than 4 seismic stations in

IV. Results of the Study
It has been confirmed that many micro-earthquakes occur in the study area by applying waveform correlation detector to the continuously recorded earthquake data. Results of initial analysis indicate 729 earthquakes occurred and recorded by more than 4 seismic stations in the study area. Their locations are determined by routine earthquake location technique. A smaller area with 20 km× 20 km has been selected for the study of detailed micro-seismic activity. More than 320 earthquakes occurred in the area between 2010 and 2014 including earthquakes with magnitude 3.5 and 2.2 in 2014. Joint hypocenter determination has been used to relocate earthquakes in the area. Relocation results are carefully examined along with the information on the geological map of Korea. In order to ensure reliable earthquake locations, knowledge of subsurface velocity structure is required. We used VELEST program package to define 1-D minimum velocity model and used the results for routine earthquake locations and precise relocations.
An earthquake with magnitude 3.5 occurred in the study area in September 23, 2014. The earthquake is accompanied by many micro-earthquakes before and after the main event. Examination of continuous data shows the earthquake sequence started with a very small earthquake in September 21 and lasted until December 2014. 31 micro-earthquakes with magnitude as small as 0.0 are identified. Focal mechanism solution using waveform inversion indicates the reverse fault with 153/46/71 (strike/dip/rake) or 360/47/109 are responsible for the earthquake.
Many capable faults are observed in the east of the Ulsan fault in the study area. Apparently, some of the faults are related in geometry, sense of motion and their locations. If they are related and approximated to a continuous single fault, the length can reach over 20 km and more than 3 slips since late Pleistocene. Locations of micro-earthquakes in the study coincide with the location of capable faults. It is suspected the Ulsan fault and Yeonil Tectonic Line are also related to the micro-seismic activity revealed in the study.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 보고서 요약서 ... 3
• 요약문 ... 4
• Ⅰ. 제목 ... 4
• Ⅱ. 연구개발의 목적 및 필요성 ... 4
• Ⅲ. 연구개발의 내용 및 범위 ... 4
• Ⅳ. 연구개발결과 ... 5
• Ⅴ. 연구개발결과의 활용계획 ... 6
• SUMMARY ... 7
• CONTENTS ... 10
• 목차 ... 11
• 제1장 연구개발과제의 개요 ... 12
• 제2장 국내외 기술개발 현황 ... 16
• 제3장 연구개발수행 내용 및 결과 ... 18
• 3.1 한반도 남동부 경주 주변지역 지질 ... 18
• 3.2 지진다발 지역 ... 24
• 3.3 경주지역 역사지진 및 계기지진 현황 ... 32
• 3.4 연구지역 1차원 속도모델 ... 37
• 3.5 지진 파형 자료 수집 및 미소지진 검출 ... 38
• 3.6 인공지진 ... 46
• 3.7 지진발생위치 결정 ... 49
• 3.8 JHD 방법을 이용한 지진발생위치 정밀 재결정 ... 56
• 3.9 2014년 9월 23일 발생한 규모 3.5 지진의 단층면해 ... 65
• 3.10 경주지역 미소지진 발생현황과 단층분포 ... 69
• 제4장 목표달성도 및 관련분야 기여도 ... 70
• 제5장 연구개발결과의 활용계획 ... 71
• 제6장 연구개발과정에서 수집한 해외과학기술정보 ... 72
• 제7장 연구시설 · 장비 현황 ... 73
• 제8장 참고문헌 ... 74
• 부록 ... 76
• 끝페이지 ... 207