The 1st Annual Meeting of the Project of Seismic Hazard Assessment for the Next Generation Map:
Strategic Japanese-Chinese-Korean Cooperative Program

Some studies on the 1952 earthquake
near Pyeongyang, North Korea
Tae-Seob Kang
Department of Earth Environmental Sciences, Pukyong National University, Korea

Myung-Soon Jun
Earthquake Research Center, Korea Institute of Geoscience and Mineral Resources, Korea

27 November 2011, Harbin Institute of Technology

Historicalearthquake
A.D. 2~1904
 Intraplate region withmoderate seismicity
 About 2,000earthquakes during
about 2,000 years
 About 50 earthquakes
with fatalities anddamagesInstrumentallyrecorded
earthquake
A.D. 1905~1996
 Installation of amodern seismographin Incheon during
1905
 About 20 earthquakes
over magnitude 4.5 in
the 20th century
 No significantly large,
damaging earthquakes
in the instrumental
periodTemporal variation of seismicity in Korea
100
90
80
70
60

Number50
40
30
20
10

40

1-9C
10-14C(Pre(Koryo)
Koryo)

515C

16C

617C

18C

Magnitude

719C

20CCentury

The seismic activity in the 16th and 17th centuries was very high.

Seismic Activity since 1978

• Since 1978, seismograph stations are continually increasing.
• Detection capability of micro earthquakes has been improved.
• However, there is no obvious evidence on variation of seismic activity.
5

I. The 19 March 1952 earthquake near Pyeongyang, North Korea• Importance– Presumably the largest earthquake
in the Korean Peninsula since 1905
– Largely unknown earthquake
information due to the Korean War– No seismograph station in theKorean Peninsula– Highly significant to seismic hazard
in the Korean Peninsula• Estimated magnitude– Rustanovich et al.(1963): M=6.3– 中国国家地震局科技情報中心 (1987):Ms=6.5– Yuche Li(2001): M=6.5– Ishikawa et al.(2008): Md=6.5

1980
19521982

2007

1978

1996

1978

2004

1936

(Ishikawa et al., 2008)

II. Collection of data related to the 1952 earthquake• Searching for global
observations of the1952 earthquake from
ISC Bulletin• Figuring out whether
each station has theseismograms of theevent or not• Collecting informationon the type ofseismograph andpaper, and recording
parameters during theearthquake

III. Obtainment of analog seismograms and digital conversion

Example of theanalog seismograms

Digitization• Obtainment of the analog seismograms of the 1952 earthquake fromthe eight seismograph stations in the neighborhood countries– Japan: Abuyama, Matsushiro, Mizusawa seismograph stations– China: Zikawei, Nanking seismograph stations– Russia: Vladivostok, Sverdlovsk, Pulkovo seismograph stations• Digital conversion to extract seismic traces from the images of analog
seismogramsAnalog-to-digital conversion••••

Extraction of seismic traces from the image of analog
seismograms: Teseo software (Pintore et al. 2005)
Difficulties in digitizing the raw seismograms: low resolution, bad
continuity of seismic trace
Successful digitization of the analog seismograms from theAbuyama, Matsushiro, and Sverdlovsk seismograph stations
among a total of the eight stations
Correction of instrumental response and geometry– Instrumental responses of the three stations– Lack of information on the geometry of instruments: arm length supporting
pen of the recording system, angle between pen and paper– Hard to correct the recording curvature of the analog seismograms– Implicit errors in the analysis of seismic source parameters through waveformmodeling

9

Abuyama0Matsushiro

11

Sverdlovsk

12

IV. Source parameters of the 1952 earthquake• Arrival times– ISC Bulletin– Travel-time report fromJapanese seismograph stations• Determination of epicenter using
grid-search method based on
travel-time data
• Determination of origin time from
Wadati diagram using travel-time
data: 1952/03/19-18:04:15(localtime)

Epicenter: 125.84ºE, 38.77ºN(about 30 km SSE of Pyeongyang)IV. 파형모델링
• Synthetic seismograms: Mineos(Masters et al. 2007)• Depth: 10 km fixed• Velocity structure: PREM model• Lowpass filter < 10 s• Waveform fitting on one-cycle swing
including the largest peak
• Seismic moment– 2.45x1025 dyne-cm (Mw = 6.17)• Fault-plane solutions– Strike 120, dip 90, rake 340– Strike 210, dip 70, rake -180
– NE-SW and NW-SE strike-slip fault

V. Summary on the source parameters of the 1952 earthquake•

Origin time: 1952/03/19, 18:04:15 (local time)•

Epicenter: 125.84E, 38.77N (near Pyeongyang)•

Magnitude: Mw 6.2•

Fault plane solutions (strike, dip, rake)– (120, 90, 340)/(210, 70, -180)– NE-SW and NW-SE strike-slip fault[postscript]- This is on-going project.
- More data would be highly helpful for upgrading the quality of thesource parameters.
- Thus, if you have any connection on seismograph stations which wereoperated in 1952, we would appreciate it if you inform me of it.