BRI

Strong Ground Motions

2024 Noto Peninsula Earthquake (Mw7.5)

IISEE, Building Research InstituteInitial release: January 2, 2024
Last updated: January 9, 2024

This report contains preliminary analysis results.
JMA strong-motion data at stations 42325 (Ushitsu, Noto) and 47600 (Fugeshimachi, Wajima) were not used.

Observed PGAs/PGVs (Horizontal comp.)
1467.8 cm/s2
K-NET Ohya
(ISK001)

cm/s2

1626.4 cm/s2
K-NET Wajima(ISK003)132.9 cm/s
K-NET Shoin(ISK002)2824.9 cm/s2
K-NET Togi
(ISK006)

142.2 cm/s
K-NET Anamizu(ISK005)

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132.9 cm/s
KiK-net Uchiura(ISKH03)○: 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.

cm/s

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Observed PGAs/PGVs (UD comp.)

48.7 cm/s
K-NET Shoin(ISK002)cm/s2
1109.9 cm/s2
K-NET Wajima(ISK003)75.3 cm/s
K-NET Ohya
(ISK001)

1201.9 cm/s2
KiK-net Togi
(ISKH04)

62.0 cm/s
K-NET Wajima(ISK003)cm/s

1141.8 cm/s2
K-NET Togi(ISK006)○: NIED stations, □: JMA seismic intensity stations, △: LG seismic intensity stations

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

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.
※ Crustal earthquake (depth=10 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%)
ISK003

ISK001

ISKH01

ISKH02

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Responses of pSv >165 cm/s (T=1–2 s) wereobserved at following stations.

ISK002
ISK005
ISKH04

ISKH03
41333

42324

JMA41333 (Nanao), 42324 (Shika)

ISK015
ISK007K-NET
ISK001 (Ohya), ISK002 (Shoin), ISK003 (Wajima),
ISK005 (Anamizu), ISK007 (Nanao),
ISK015 (Omachi)
KiK-net
ISKH01 (Suzu), ISKH02 (Yanagida),
ISKH03 (Uchiura), ISKH04 (Togi)

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

BSL (soil type: 2)

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BRIAttenuation characteristics of response spectra (h=5%)

NIED stations
JMA stations

cm/s2

Recorded accelerograms at K-NET ISK005 (Anamizu)

Time (s)Station ISK005 shows accelerograms indicative of “cyclic mobility” in the horizontal
components, suggesting the occurrence of liquefaction phenomena.

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Summary (1)The largest PGA was recorded at K-NET station Togi (2827.8 cm/s2),
while the largest PGV was recorded at K-NET station Anamizu (142.7 cm/s).
PGAs of >1000 cm/s2 were recorded even in the vertical component
at four NIED stations.
Response of pSv >165 cm/s (h = 5%, T=1–2 s) were observed at least 12 stations.
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 also used strong-motion data from the Japan Meteorological Agency (JMA) seismic intensity stations.
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).

Response acceleration spectrum Sa and response periods
Colored Line: NIED K-NET/KiK-net strong-motion (Equivalent damping factor＝5％)

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Sa - Sd curve and response periods

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Colored Line: NIED K-NET strong-motion (Equivalent damping factor＝15％)

Base shear coefficient CB＊(＊effective mass conversion)

Details of strong ground motions observation

Year

Magnitude Data Source

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Month Date

Earthquake Name

2011

311Tohoku

1995

117

Kobe

7.3 JMA

JMA_KOBENS

1995

117Kobe7.3 RTRI

TakatoriNS2007

716

NiigataChuetsuOki

6.8 K-NET

Kashiwazaki

NIG018NS2016

416Kumamoto

7.3 KiK-net

Mashiki

KMMH16EW

2023

55IshikawaNoto

6.3 K-NETShoin

ISK002

NS/EW

2024

11Noto

7.6 K-NETTogi

ISK006

NS/EW

2024

1

1

Noto

7.6 K-NET

Wajima

ISK003

NS/EW

2024

11

Noto

7.6 K-NETAnamizu

ISK005

NS/EW

2024

11

Noto

7.6 K-NET

Shoin

ISK002NS/EW

9 K-NET

Site Name
Tsukidate

Site ID
MYG004NS/EW
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Summary (2)• The strong ground motions observed at Anamizu (ISK005) and Shoin(ISK002) have the same or larger amplitudes in the Sa-Sd compared tostrong ground motions observed in the recent earthquakes in Japan.

• From the Sa-Sd curve assuming a 15% equivalent damping ratio, theresponse displacement (Sd) of Anamizu (ISK005) at the period of 1 to 2
seconds was 30 to 90 cm, which was larger than Togi (ISK006), Wajima(ISK003).
• The response acceleration (Sa) of the North-South (NS) components ofAnamizu (ISK005) showed large values at around the period of 1.5
second.
Acknowledgement:
We used strong motion data provided by NIED(K-NET, KiK-net), JMA, and, RTRI.
Sa-T and Sa-Sd were calculated using the View Wave by Kashima, BRI.