M7.3 Namie, Japan

Post-Event Analysis | Summary
Posting Date: March 23, 2022, 8:00:00 PM

Verisk estimates that insured losses to properties from the March 16 M7.3 earthquake that struck offshore the island of Honshu, Japan, will be between JPY 240 billion (~USD 2 billion) and JPY 490 billion (~USD 4 billion). Of that, between JPY 50 billion (~USD 400 million) and JPY 100 billion (~USD 820 million) can be attributed to commercial and industrial properties.

ALERT™ subscribers can download Touchstone® and Touchstone Re™ custom event sets of five scenarios for this event, a Touchstone-ready shapefile of the estimated ground motion for the median scenario, and loss-based similar stochastic events from the Downloads tab on the ALERT website. The information provided herein is strictly confidential and is solely for the use of our clients; disclosure to others is prohibited unless noted in your software license.

Verisk’s loss estimates are gross of government recoveries (i.e., prior to the application of the Japanese Earthquake Reinsurance scheme). They explicitly capture damage from ground shaking, liquefaction, and fire following. Losses are dominated by shake damage in Verisk’s scenarios, with a very small contribution from liquefaction and fire-following. Note that Verisk’s estimates are based on assumptions about take-up rates in Japan (the percentage of properties actually insured against the earthquake peril), which are uncertain. The range in loss estimates also reflects uncertainty in the slip distribution on the fault plane, modeled ground motion, and damage estimation. The assumed exchange rate is 1 JPY = 0.0083 USD.

Seven days after the quake, including a long holiday weekend in Japan, damage reports are still being filed. At least 241 casualties have been attributed to this earthquake, three of them deaths. The Japan Fire and Disaster Management Agency (FDMA) estimates that more than 580 buildings in Fukushima Prefecture and more than 570 buildings in Miyagi Prefecture were damaged. Other impacts from the quake include power and water outages; damage to highways, rail lines, viaducts, and other infrastructure; short-term cancellation of some train service; and significant supply chain and production interruption for the automotive and paper industries.

Verisk’s insured loss estimates include:
• Insured physical damage to onshore property (residential, commercial/industrial, mutual), both structures and their contents, and from ground shaking, fire-following, and liquefaction

Verisk’s insured loss estimates do not include:
• Losses to uninsured properties
• Losses to land
• Losses to infrastructure
• Losses to automobiles
• Business interruption losses, both direct and indirect
• Workers’ compensation losses
• Losses to civil engineering (railway) risks, marine cargo and marine hull risks, aviation risks
• Risks, Transit warehouse risks, movable all risk, and personal accident risks
• Loss adjustment expenses
• Losses from non-modeled perils, such as landslide
• Demand surge—the increase in costs of materials, services, and labor due to increased demand following a catastrophic event

The March 16, 2022, M7.3 Namie, Japan, earthquake with a relatively deep focal depth of 63 km that struck near the east coast of Honshu occurred as the result of thrust faulting near the Japan Trench subduction zone plate boundary interface between the Pacific and North America plates. Moment tensor solutions indicate that slip occurred along a fault striking near north-south moderately dipping either to the east or west. The location, depth, preliminary results on the fault source inversion of seismic and GPS data indicate that this earthquake has likely ruptured the subducting Pacific plate, or an intra-plate earthquake. Intra-plate earthquakes typically release higher stress and energy than typical subduction zone earthquakes along the plate interface. The very high ground motion experienced along the coastal areas of Honshu is likely the result of intra-plate rupture.

The Verisk Earthquake Model for Japan and Japan Seismicity

The Verisk Earthquake Model for Japan, last updated in 2021, incorporates Japan’s Headquarters for Earthquake Research Promotion’s (HERP’s) view of seismic hazard in some cases as well as our own insights into the seismicity and ground motion model. Verisk’s hazard footprint for the March 16, 2022, M7.3 earthquake is simulated using the detailed source parameters based on inversion of GPS and seismic data along with strong motion recordings at hundreds of stations. Our scenarios closely capture the high ground shaking intensity of the high-frequency ground motions of this quake due to the source characteristics and large spatial variations in site conditions. Like many previous significant earthquakes in Japan, high-frequency ground motions tend to be amplified considerably in areas with shallow soft sediments such as valleys and the coast.

The March 16, 2022, earthquake was preceded by an M6.4 foreshock approximately two minutes earlier. The epicenter of the mainshock was located ~100 km from the epicenter of the March 11, 2011, M9.0 Tohoku earthquake. The Tohoku earthquake was widely felt on the islands of Honshu and Hokkaido and generated a significant tsunami that led to extensive destruction along the Japanese coast and propagated throughout the Pacific Ocean basin. In the past century, 33 earthquakes of M7 or greater have occurred within 250 km of the March 16 earthquake, including 7 earthquakes >M7 since the March 2011 M9.0 earthquake.

Earthquakes in the Japan Trench with relatively deep focal depths tend to produce very high ground motions in coastal areas. The March 11, 2011, M9.0 Tohoku earthquake is an example of an earthquake with a relatively deep focal depth striking the Japan Trench that had very high ground motion observations. Tohoku was not only the first subduction earthquake exceeding M8.5 in the Japan Trench since 1900, but it was also the largest earthquake to strike Japan since record-keeping began in the 1600s. Before Tohoku, the Japan government’s seismic hazard models developed by HERPJapan’s Headquarters for Earthquake Research Promotion (HERP) had relied heavily on historical seismicity. The Tohoku earthquake, however, clearly proved that the past was not a reliable indicator of future seismic activity; limited historical data had led to an underestimation of hazard.

The Tohoku earthquake became the most widely instrumented earthquake in history, generating copious ground motion data, damage observations, and detailed insurance claims data. Since 2011, Verisk seismologists, HERP, and many other members of the scientific community have undertaken a broad range of studies to better understand regional seismotectonics in Japan. HERP made several key updates to their 2019 model, including a higher rate of seismicity for inter- as well as intra-slab earthquakes for all subduction zones. The HERP model explicitly includes these seismic sources at relatively deep depths in their 2019 model.

Impacts to Residential Buildings and Public Utilities

Right after the quake, several power plants were shut down, so more than 2.2 million homes had their electricity temporarily cut in 14 prefectures, including the Tokyo region. Although most electric power companies gradually restarted operations, the Hirono Thermal Power Station Unit 6 in the town of Hirono, Fukushima Prefecture, and the Shinchi Thermal Power Station Unit 1 of Soma Kyodo Thermal Power Station—which both send electric power to the Tohoku Electric Power Company (TEPCO) jurisdiction—were still out of operation, so supply capacity was lower within the TEPCO jurisdiction, while demand remained tight because of low temperatures and heating needs in the area. TEPCO was able to tap into a power interchange supplied by other companies after the earthquake, which was roughly equivalent to the size of one large thermal plant. By mid-morning the day after the quake, local time, power had been restored to most areas, according to TEPCO, but TEPCO called for power saving in Tokyo, Kanagawa, Chiba, Saitama, lbaraki, Tochigi, Gunma, Yamanashi, and Shizuoka prefectures east of the Fuji River, while power came from the interchange. On March 21, TEPCO issued a “power supply and demand tight warning” for the first time ever.

In Miyagi and Fukushima prefectures, about 60,000 households were without running water after the quake. Most household have had their water restored, but even households with running water in some areas are urged not to drink it.

TEPCO said that the earthquake would not affect the operation of the Fukushima Daiichi Nuclear Power Station; however, two of the outdoor containers that store radioactive waste, such as worker's protective clothing, collapsed and more than a dozen outdoor containers were tilted, with some of the contents leaking out. No increase in radiation in the surrounding area has been confirmed. In the outdoor tank that stores previously contaminated water that has been treated, 10 water level gauges that had been confirmed as out of order were replaced and restored.

According to the Nuclear Regulatory Agency, all of the spent nuclear fuel reprocessing plants for fuel at the Higashidori Nuclear Power Station of TEPCO Tohoku Electric Power Co., Inc., and at Japan Nuclear Fuel Limited—both of which are located in Aomori Prefecture—have been shut down. No abnormalities due to the earthquake have been confirmed.

Garbage incinerator Koyo Clean Center in the City of Soma, Fukushima Prefecture, was damaged by the earthquake and residents were advised to store combustible garbage at home. A nearby vacant lot is serving as a temporary storage area also. The facility may not be up and running again for more than a month. Soma is looking into the possibility of using incineration facilities in other municipalities.

Commercial/Industrial/Supply Chain Impacts

Automotive factories

Toyota Motor Corp. stated that it would suspend operations at 11 factories for up to three days during the week of March 21 because the parts manufacturers of its business partners were damaged by the earthquake and parts procurement has been delayed. About 80% of the factories in Japan that manufacture Toyota cars will be affected, meaning that about 20,000 units will not be able to be produced. Toyota did, however, resume operations on March 17 at its factories in the town of Kanegasaki, Iwate Prefecture, and the village of Ohira, Miyagi Prefecture.

Subaru suspended operations at three factories, including its main factory in Gunma Prefecture, on March 18 and 21, due to the damage caused by the quake to the factories of its business partners.

Hitachi Astemo, an automobile parts manufacturer, shut down six factories—five engine parts manufacturing plants in southern Miyagi Prefecture and one suspension factory in northern Fukushima Prefecture[please close up space here] —after the earthquake; production was expected to resume the week of March 21 after equipment is inspected and restored.

Toshiba resumed some operations on March 17 because no major damage to the semiconductor factory in the City of Kitakami, Iwate Prefecture, was found.

A complicating factor is that automakers have already been reducing production and shutting down their factories from time to time due to the shortage of semiconductors and COVID-19 concerns.

Other Industries

Major paper manufacturer Nippon Paper Industries suspended operations indefinitely at two factories in Miyagi Prefecture in the cities of Ishinomaki and Iwanuma.

Murata Manufacturing Co., Ltd., a major electronics component manufacturer, is checking equipment and performing restoration work at a production base in the City of Tome, Miyagi Prefecture.

IHI, a major machine maker, stated that it may take time to restore the Soma factory in Fukushima Prefecture.

At Ishikoshimachi, a 100-year-old sake brewing company in the City of Tome, Miyagi Prefecture, the quake shook liquor bottles and cases of liquor. The company wasis preparing to resume business days after the quake tomorrow, but the quake has affected the shipper it uses for deliveries.

Two 40-meter-tall cranes that lift coal from ships for overland transport broke because of the quake, causing the upper half to fall away at a wharf of Soma Port in Fukushima Prefecture.
Travel Impacts

The Tohoku-Hokkaido Shinkansen train derailed in the City of Shiroishi, Miyagi Prefecture. The train was not moving fast between the Fukushima and Shiroshizaou stations at the time of the derailment; three people suffered minor injuries. Damage to overhead lines, including two cuts, were discovered in 550 places; distortion and damage to the track were discovered in 300 places; damage to 60 pieces of civil engineering equipment, such as viaducts, has been observed; and 79 observations of damage to utility poles have been confirmed. Work to repair the derailed train and restore it to service on the track has begun. The resumption of suspended service and the restoration of all connections on all lines is planned for April 20. Until then, Minister of Land, Infrastructure, Transport and Tourism Saito, who visited three places that were damaged by the derailment, intends to expand alternative transport with bus and airline companies.

Large cracks over tens of meters long have been discovered on the Tohoku Expressway in the area of the City of Shiroishi, Miyagi Prefecture. In addition, the white lines on some shoulders have shifted. The Tohoku Expressway, which runs south to north, is a national expressway and the longest in Japan at nearly 680 km. Twelve roads in the City of Soma, Fukushima Prefecture, were closed.

This is the final ALERT currently planned for this event.

Post-Event Analysis | Downloads
Posting Date: March 23, 2022, 8:00:00 PM

The information provided herein is strictly confidential and is solely for the use of Verisk clients; disclosure to others is prohibited.

Simulated Event Set

Note: These event sets are only compatible with the version 9 (2021 releases) of Touchstone and Touchstone Re.

Product	Version	Description	Download
TOUCHSTONE Re	9	Selected set of simulated scenarios with 100% Limits Assumptions
TOUCHSTONE Re	9	Selected set of simulated scenarios with Industry Policy Mix Assumptions
TOUCHSTONE	9	Selected set of simulated scenarios

Similar Stochastic Event IDs

Note: These are event IDs taken from our stochastic catalog that have similar characteristics as the current event.  They are only compatible with the version 9 (2021 releases) of Touchstone and Touchstone Re.

The ALERT team did endeavor to select loss based similar stochastic event IDs for the previous model version, however, no suitable candidate events could be identified.  The updated model explicitly added deep events of this type that had been missing from the previous HERP update.

Product	File Type	Description	Download
TOUCHSTONE / Re	Excel (xls)	Selected set of stochastic events

Additional Downloads

Note: Additional downloads related to the posting are listed below. Please use the appropriate application to view these files.

Title	File Type	Description	Download
Shapefile of Ground Motion Footprint	.zip	A shapefile of the median loss scenario (Event #3) ground motion (PGA in g) footprint
Insured Industry Losses by Prefecture	.xlsx	A spreadsheet containing insured industry losses (Industry Policy Mix assumptions) for the five custom scenarios, split by prefecture