BRI Confidential

Strong Ground Motions
Noto Peninsula, Ishikawa Prefecture earthquake on May 5, 2023

IISEE, Building Research InstituteMay 18, 2023

BRI Confidential

Observed PGAs/PGVs (Horizontal comp.)
cm/s2cm/s

729.1 cm/s2
KiK-net Suzu
(ISKH01)

676.2 cm/s2
K-NET Shoin(ISK002)58.3 cm/s
KiK-net Suzu
(ISKH01)110.1 cm/s
K-NET Shoin(ISK002)○: NIED stations, □: JMA seismic intensity stations, △: Local Government (LG) seismic intensity stations※ PGA and PGV are the maximum values of vector summation in the horizontal components.

BRI Confidential

Observed PGAs/PGVs (UD comp.)
cm/s2cm/s

702.1 cm/s2
KiK-net Suzu
(ISKH01)

376.6 cm/s2
K-NET Shoin(ISK002)22.9 cm/s2
KiK-net Suzu
(ISKH01)

39.6 cm/s
K-NET Shoin(ISK002)○: NIED stations, □: JMA seismic intensity stations, △: LG seismic intensity stations

Observed PGAs/PGVs vs GMPE (Si & Midorikawa, 1999)

BRI Confidential

NIED stations
JMA stations
LG stations※ Horizontal axis is not the “shortest distance to the fault”.
※ PGA/PGV values are the larger of the maximum values of NS and EW components.
※ Intraplate earthquake (depth=40 km) is assumed for the estimation.
※ Estimated values beyond 100 km (dashed line) are shown as reference values.

Pseudo-velocity response (pSv: 1‒2 s, h=5%)

BRI Confidential

1–2 s (peak: horizontal comp.)
KiK-net Suzu
ISKH01

K-NET Shoin(ISK002)

Responses of pSv >165 cm/s (T=1–2 s) was
observed at K-NET station Shoin (ISK002).

Attenuation characteristics of response spectra (h=5%)

BRI ConfidentialNIED stations
JMA stations

Response acceleration spectrum Sa and response periods

BRI Confidential

Sa(cm/s2) Colored Line: NIED K-NET/KiK-net strong-motion (Equivalent damping factor＝5％)
3000

2500

Shoin (ISK002)_NS

Tsukidate (2011Tohoku)_NS

Shoin (ISK002)_EW

JMA Kobe (1995Kobe)_NS
Takatori (1995Kobe)_NS

Suzu (ISKH01)_NS

Kashiwazaki (2007Niigata Chuetsu-Oki)_NS

Suzu (ISKH01)_EW

Mashiki (2016Kumamoto)_EW

2000

1500

1000500(considering Fh)
BSLJ (Soil Type3)
BSLJ (Soil Type2)
BSLJ (Soil Type1)000.511.522.533.54

Sa−Sd curve and response periods

5Sa(cm/s2) Colored Line: NIED K-NET/KiK-net strong-motion (Equivalent damping factor＝15％)

2.2

Shoin (ISK002)_NS

T=1 sec.

2Shoin (ISK002)_EW

Tsukidate (2011Tohoku)_NS

T= 1.5 sec.

Suzu (ISKH01)_NS1800

JMA Kobe (1995Kobe)_NST(sec.)

BRI Confidential
Base shear coefficient CB＊(＊effective mass conversion)

2200

2000

4.5

1.8

Suzu (ISKH01)_EW

1600

1.6

1400

T=2 sec.

Mashiki (2016Kumamoto)_EW

1200

1.4

1.2

1000

1Takatori (1995Kobe)_NS

Kashiwazaki (2007Niigata Chuetsu-Oki)_NS

8000.86000.64000.4

BSLJ (Soil Type3) (considering Fh)2000.2

BSLJ (Soil Type2) (considering Fh)
BSLJ (Soil Type1) (considering Fh)

001020304050607008090100110120130140

Sd ＊(cm)(＊relative displacement)

BRI Confidential

Summary–Noto Peninsula, Ishikawa Prefecture earthquake on May 5, 2023–
The largest PGA was recorded at KiK-net station Suzu (729.1 cm/s2),
while the largest PGV was recorded at K-NET station Shoin (110.1 cm/s).
Response of pSv >165 cm/s (T=1–2 s) was observed at Shoin (ISK002).
Strong ground motions observed at Shoin (ISK002) and Suzu (ISKH01) havesmall amplitudes in the Sa-Sd compared to those observed during recent
earthquakes in Japan.
From the Sa-Sd curve assuming a 15% equivalent damping ratio, the response
displacement (Sd) of Shoin (ISK002) at the period of 1 to 2 seconds was 20 to 40 cm,
which was larger than Suzu (ISKH01).

BRI Confidential

Summary (cont.)
The response acceleration (Sa) of the North-South (NS) and the East-West (EW)
components of Shoin (ISK002) showed large values at around the period of 1 s.
Acknowledgments:
We used K-NET and KiK-net strong-motion data provided by
the National Research Institute for Earth Science and Disaster Resilience; NIED), Japan
https://www.doi.org/10.17598/NIED.0004
We used accelerograms from JMA seismic intensity meters and PGA/PGV information provided by local governments (SK-net).
We used strong motion data provided by RTRI.
We used hypocenter information determined by NIED Hi-net.
Response spectra were calculated using the subroutine program developed by Osaki (1994).
Figures were prepared using Generic Mapping Tools (GMT: Wessel and Smith, 1998).
Sa-T and Sa-Sd were calculated using the View Wave by Kashima, BRI.