Natural Disasters in Japan

Japan is known for its natural beauty throughout the world with its abundant seas, lakes, and mountains. Many international travelers take advantage of the convenient public transportation to enjoy these natural wonders of Japan. However, this exposes travelers to potential danger from natural disasters. Many natural disasters are unique to Japan and thus can be unfamiliar to people from parts of the world with distinctively different environments and climates. While mortalities remain extremely rare among foreign travelers in Japan, we recommend preparing in advance for potential emergencies.
Below is a summary of some of the major natural disasters that usually occur in Japan. We provide basic descriptions of these disasters, warning and advisory information about them, as well as countermeasures travelers can take to minimize negative impacts of the disasters. We believe this information will be useful during emergencies.

Click on the links below to access information on each type of disaster:
1. Earthquakes and Tsunamis
2. Heavy Rains and Typhoons
3. Snowstorms
4. Volcanic Eruptions
5. Extreme Heat and Other Disasters

1. Earthquakes and Tsunamis

Description

Earthquakes refer to the sudden shaking of the ground. As objects physically move during earthquakes, your surroundings can be damaged. Be careful inside rooms and buildings, as people can be injured by falling objects. Stronger earthquakes can change entire structures of buildings and natural landscapes, leading to destruction that can injure people.

Earthquakes that occur in the ocean have the potential to initiate tsunamis, which are massive waves generated by fluctuations on the ocean surface. Tsunamis that head toward coastal cities and towns can cause flooding, which in turn damages buildings, objects, and people.

Warnings and Advisory Information

Both earthquakes and tsunamis are caused by seismic activity, for which intensity describes the degree of shaking. The Japan Meteorological Agency ranks seismic intensity across ten levels ranging from 0 to 7 (please see the table below). Magnitude (M) is the energy of the earthquake. Even an earthquake with a small magnitude could have a large seismic intensity in areas near its source. Japanese TV outlets such as the NHK usually provide live reporting of all seismic activities measured 4 and above.

Human perception and reaction
Seismic intensity：Human perception and reaction
0: Imperceptible to people, but recorded by seismometers.
1: Felt slightly by some people keeping quiet in buildings.
2: Felt by many people keeping quiet in buildings. Some people may be awoken.
3: Felt by most people in buildings. Felt by some people walking. Many people are awoken.
4: Most people are startled. Felt by most people walking. Most people are awoken.
5 Lower: Many people are frightened and feel the need to hold onto something stable.
5 Upper: Many people find it hard to move; walking is difficult without holding onto something stable.
6 Lower: It is difficult to remain standing.
6 Upper: It is impossible to remain standing or move without crawling. People may be thrown through the air.
7: It is impossible to remain standing or move without crawling. People may be thrown through the air.

Source: “Human perception and reaction, indoor situation, outdoor situation,” homepage of the Japan Meteorological Agency: https://www.jma.go.jp/jma/en/Activities/inttable.html

Tsunami Warning/Advisory

The Japan Meteorological Agency issues alerts about incoming tsunamis based on their size and geographical distribution. Ranging in magnitude, from relatively weak advisories to more urgent warnings and emergency warnings, these alerts are relayed by TV stations and over the web by media outlets such as the NHK. In the below table, we have summarized the content and definitions of different alerts.

Tsunami Warning/Advisory
Major Tsunami Warning**
Indication：Tsunami height is expected to be greater than 3 meters.
Expected damage and action to be taken：Wooden structures are expected to be completely destroyed and/or washed away; anybody exposed will be caught in tsunami currents.
Evacuate from coastal or river areas immediately to safer places such as high ground or a tsunami evacuation building.

Tsunami Warning
Indication：Tsunami height is expected to be up to 3 meters.
Expected damage and action to be taken：Tsunami waves will hit, causing damage to low-lying areas. Buildings will be flooded and anybody exposed will be caught in tsunami currents.Evacuate from coastal or river areas immediately to safer places such as high ground or a tsunami evacuation building.

Tsunami Advisory
Indication：Tsunami height is expected to be up to 1 meter.
Expected damage and action to be taken：Anybody exposed will be caught in strong tsunami currents in the sea. Fish farming facilities will be washed away and small vessels may capsize.Get out of the water and leave coastal areas immediately.

** Major Tsunami Warnings are issued in the classification of Emergency Warnings.
Detailed information on Emergency Warnings is provided on the Emergency Warning System web page.

Source: “Tsunami Warning/Advisory” homepage of the Japan Meteorological Agency: http://www.data.jma.go.jp/svd/eqev/data/en/guide/tsunamiinfo.html#info1

Countermeasures

Proper countermeasures for earthquakes and tsunamis vary greatly depending on where you happen to be when disaster strikes. In the below paragraphs, we look at specific measures to take based on location.

If you are outside on the street, be sure to check whether billboards, window glass, and concrete blocks can fall over or drop from high places. Observe your immediate surroundings with calm and move to areas that seem to be the safest from the possibility of being hit with falling objects.

If you are in underground pedestrian zones, stand by large columns or walls. Follow instructions given by staff members in the area rather than rushing toward the nearest exit. Remain calm even during blackouts as emergency lighting will automatically switch on. If a fire breaks out in the immediate area, cover your mouth and nose with a handkerchief or a towel, lower your body, and move along the wall in the same direction as the smoke is flowing to escape.

If you are on the platform of a train station, you should move immediately to the nearest column to prevent falling into the train tracks or being hit with falling objects. If the platform is too crowded to allow for free movement, crouch down to the ground level and wait for the shaking to stop. Do not rush for the nearest exit or go in the train tracks. Stay on the platform and follow the instructions given by nearby staff members.

If you are inside a train, be mindful that the train can make a sudden emergency stop, causing people injury from hitting others or falling to the ground. If you are seated, you should put your bags over your head for protection. If you are standing, crouch down on the ground. For crowded trains where crouching is not possible, you should hold firmly onto handrails or straps to prevent falling over. Follow instructions given by crew members after the shaking stops.

If you are in a coastal area, immediately move to an area with higher ground. Continue to evacuate toward higher areas even after the initial tsunami passes, as tsunamis may repeatedly strike the same area multiple times within a short period of time. Do not return to coastal areas until it is publicly announced that it is safe to do so.

Source: “Actions when Earthquakes Occur,” e-College (Fire and Disaster Management Agency of the Ministry of Internal Affairs and Communications)
http://open.fdma.go.jp/e-college/study00/kiso/saigai_chishiki/jishin/06/index.html

Reference: page 30-31, “Disaster Preparedness Tokyo,” Tokyo Metropolitan Government

2. Heavy Rain and Typhoons

Description

Persistent heavy rains accompanied by strong winds are known as rainstorms. Rainstorms can disrupt travel schedules by shutting down public transport and making it impossible to walk outside. They can also create lasting damage to urban infrastructure. In areas with insufficient countermeasures, flooding can damage interiors of buildings while winds blow away certain objects. Confirm the locations of nearby designated evacuation areas to avoid being injured by flooded electrical systems and/or being hit by flying objects. Low-pressure systems formed above tropical waters are known as tropical low-pressure systems. Those that exist in northwest Pacific (north of the equator and west of 180 E) or the South China Sea and has an average 10-minute maximum speed of at least 17m/s (or 34 knots, wind force of 8 on the Beaufort scale) are known as typhoons.

Source: “What is a Typhoon,” homepage of the Japan Meteorological Agency
https://www.jma.go.jp/jma/kishou/know/typhoon/1-1.htm

Warnings and Advisory Information

The Japan Meteorological Agency issues various alerts about incoming rainstorms and typhoons based on their intensity and geographical information. Ranging in magnitude from relatively weak advisories to more urgent warnings and emergency warnings, these alerts are relayed by TV stations and over the web by media outlets such as the NHK. In the below table, we have summarized the content and definition of different alerts.

Categories and Definitions of Special Alerts regarding Heavy Rains and Typhoons from Japan Meteorological Agency

Heavy rain advisory: Issued when it is forecasted that heavy rain will cause landslides or flooding. This advisory will continue even after the rain has stopped if there is still the risk of landslides and other disasters.

Heavy rain warning: Issued when it is forecasted that heavy rain will cause major landslides or flooding. To clarify the risks to be noted, the issuance will be “Heavy rain warning (Landslides), Heavy rain warning (Flooding), or Heavy rain warning (Landslides, Flooding). This warning will continue even after the rain has stopped if there is still the risk of major landslides and other disasters.

Heavy rain emergency warning: Issued when heavy rain of an intensity seen only once every few decades is forecasted due to typhoons or concentrated rainfall, or when a typhoon with an intensity observed only once every few decades or heavy rain from a comparable tropical low-pressure system is forecasted. When issued, it is forecasted that there is an extremely high risk of major landslides or flooding. This emergency warning will continue even after the rain has stopped if there is still a serious risk of major landslides and other disasters.

Flood advisory: Issued when it is forecasted that heavy rain or snowmelt upstream can cause a significant increase in water volume downstream that risk flooding. Possible impact from flooding includes rivers and streams increasing in volume, as well as damaging of levees.

Flood warning: Issued when it is forecasted that heavy rain or snowmelt upstream can cause a significant increase in water volumes downstream that risk serious flooding. Possible impacts from flooding include rivers and streams increasing in volume or overflowing, as well as damaging and breaking of levees.

High wave advisory: Issued when there is the risk of disasters, including accidents and damage to coastal facilities due to high waves.

High wave warning: Issued when there is the risk of serious disasters, including accidents and damage to coastal facilities due to high waves.

High wave emergency advisory: Issued when it is forecasted that high waves will be produced by a typhoon with an intensity observed only once every few decades, or from heavy rain from a comparable tropical low-pressure system.

Storm surge advisory: Issued when there is the risk of disasters occurring through the abnormal rise of the ocean surface due to typhoons and low-pressure systems.

Storm surge warning: Issued when there is the risk of serious disasters occurring through the abnormal rise of the ocean surface due to typhoons and low-pressure systems.

Storm surge emergency warning: Issued when it is forecasted that storm surge will be produced by a typhoon with an intensity observed only once every few decades or heavy rain from a comparable tropical low-pressure system.

Gale advisory: Issued when there is the risk of disasters occurring from strong winds.

Storm warning: Issued when there is the risk of serious disasters occurring from strong winds.

Storm emergency warning: Issued when it is forecasted that storm will be produced by a typhoon with an intensity observed only once every few decades or heavy rain from a comparable tropical low-pressure system.

Thunderstorm warning: Issued when there is the risk of disasters occurring from extreme weather patterns such as lightning, hail, heavy rains, or sudden gusts of wind.

Source: “Type and content of different meteorological warnings,” homepage of the Japan Meteorological Agency: https://www.jma.go.jp/jma/kishou/know/bosai/warning_kind.html

Countermeasures

1.Collect Relevant Information

First, it is important to gather relevant information. You should pay attention to weather information about heavy rains and typhoons broadcasted on radio, TV, and over the Internet. Minimize outside activities that are not absolutely necessary. Return your place of accommodation immediately in preparation for an emergency. Do not go near overflowing streams, gutters, and base of slopes. When the risk of disaster increases, specific instructions will be given by municipal authorities through various means and loudspeaker-mounted vehicles. Follow those instructions whenever possible.

2. Evacuation

Even if no specific instructions for evacuations are given, different physical conditions mean that some accommodations can already be in danger. Evacuate as soon as you sense danger. In particular, children, the elderly, and those with physical handicaps should be evacuated in advance.

If you happen to be outside when a typhoon approaches, move immediately to a nearby building and remain there until the typhoon subsides. Either way, do not go out to repair windows or roofs while the winds are still raging.

Water at the knee-deep level makes walking difficult. In cases of heavy rain, make sure to evacuate to higher ground before the water level reaches knee-deep. If the water is moving rapidly, evacuate immediately, as the speed of moving water makes moving much more difficult. e For those in underground areas, move immediately above-ground to a designated evacuation area, or a sturdy nearby building, preferably at least two stories high.

During evacuations, one should wear shoes, such as sneakers with shoelaces, that are difficult to take off and easy to walk in. Shoes that are easily taken off, such as long boots, are not recommended. While walking in areas overflowing with water, one should be mindful of potential dangers beneath the water. Use a long stick to check for safety beneath the water before walking into the water. In areas where water is flowing rapidly, groups of people should try themselves together to prevent separation.

After returning to the place of accommodation, one should check the safety of the building. In particular, check if there are damages to electrical lines, and report immediately to local utility companies and other neighbors should there be any damages. Wait for professionals to show up to repair the damages. Do not attempt to repair the damages without professional assistance.

Source: “Actions to be Taken in Response to Dangers from Wind- and Water-Caused Disasters,” e-College (Fire and Disaster Management Agency of the Ministry of Internal Affairs and Communications)
http://open.fdma.go.jp/e-college/study00/kiso/saigai_chishiki/fuuzuigai/04/index.html

Reference: page 149, “Disaster Preparedness Tokyo,” Tokyo Metropolitan Government

3. Snowstorms

Description

Heavy snows accompanied by strong winds are snowstorms. Snowstorms can shut down public transport, making certain locales inaccessible and cause unforeseen changes to your travel schedule. In some regions, snowstorms can pose additional dangers to travelers’ physical well-being due to the extremely low temperature that accompanies them. Damage to infrastructure from snowstorms can take longer to clear than those caused by rainstorms. Travelers are compelled to fight off cold temperatures on their own during those resulting periods of damage and inaccessibility.

In mountainous areas, snowstorms can trigger possibilities of avalanches, where snow accumulated on sloped areas slides downhill, entrapping more snow on the slopes in the process. People who happen to be on sloped areas with accumulated snow can be carried downhill by the rapidly moving snow, with potentially fatal injuries from hitting trees, rocks, and other physical objects in and/or near the avalanche.

Warnings and Advisory Information

Snowstorms in Japan are a winter phenomenon particularly in the northern and western coasts of the country. Travelers to Hokkaido, Tohoku, and the northern coastal stretches of the Sea of Japan are vulnerable to snowstorms. It is advisable to check warning and advisory on the matter before making the journey to these regions during the winter in order to prevent being unnecessarily stranded in undesirable areas and situations. Like for rainstorms, the Japan Meteorological Agency issues a variety of less urgent advisories and more urgent warnings regarding snowstorms based on their intensity and geographical region.

Categories and Definitions of Special Alerts regarding Snowstorms from Japan Meteorological Agency

Heavy snow advisory: Issued when there is the risk of disasters occurring due to heavy snow, including damages to residences and disruption in transport from falling or accumulated snow.

Heavy snow warning: Issued when there is the risk of major disasters occurring due to heavy snow, including damages to residences and disruption in transport from falling or accumulated snow.

Heavy snow emergency warning: Issued when it is forecasted that there will be heavy snow of an intensity observed only once every few decades.

Gale and snow advisory: Issued when there is the risk of disasters occurring from strong winds accompanying snow. In addition to strong winds, the advisory also warns about the risk of disasters resulting from the reduction of visibility from snow blown by strong winds. However, it does not mean heavy snow and strong wind. A heavy snow advisory is issued when there is the risk of disasters occurring due to heavy snow.

Snowstorm warning: Issued when there is the risk of serious disasters occurring from gales accompanying snow. The warning is also given about the risk of serious disasters resulting from the reduction of visibility from snowstorms. However, it does not mean heavy snow and strong wind. Heavy snow warning is issued when there is the risk of serious disasters occurring due to heavy snow.

Snowstorm emergency warning: Issued when it is forecasted that a powerful typhoon or low-pressure system with an intensity observed only once every few decades produce gales accompanying snow.

Source: “Type and content of different meteorological warnings,” homepage of the Japan Meteorological Agency
https://www.jma.go.jp/jma/kishou/know/bosai/warning_kind.html

Countermeasures

You should avoid going outside during snowstorms. As soon as the heavy snow is forecasted, stock up on readily consumable foods in case you cannot venture outside for days at a time. Prepare warm clothing, blankets, and bedding so that you can stay warm inside should electricity be cut off during snowstorms.

If you’re walking outside during a snowstorm, take necessary precautions to prevent slipping on icy roads and sidewalks. Wear slip-resistant shoes or snow boots, and walk slowly to check for slippery areas.

If possible, do not ride bicycles and minimize the use of a car. If you cannot avoid using vehicles, make sure the vehicle is equipped with winter tires and/or take other precautions to avoid slippage. Make sure the vehicle is driven slowly and maintain large distance with vehicles ahead of it to reduce risks of collisions and other road accidents. Bring emergency food and blankets if there is a possibility of the vehicle being stuck in remote areas where it would be hard to get help.

Reference: page 159, “Tokyo Disaster Preparedness”, Tokyo Metropolitan Government

4. Volcanic Eruptions

Description

Japan lies on the Pacific Ring of Fire, a region known for active volcanic activities. The Japanese archipelago is home to dozens of active volcanoes, with the most famous being Mt. Fuji. 21 of the active volcanoes are within the Greater Tokyo area alone. Many of the active volcanoes could produce volcanic eruption. Volcanic eruption is the spewing of volcanic ash into the air and flowing of extremely hot volcanic lava into the area surrounding the volcano.

Lava can destroy entire communities lying next to erupted volcanoes and bring the local transport system to a halt as people are evacuated from the general area. Volcanic ash can reduce visibility in a wider area and cause respiratory sickness. Please avoid areas affected by volcanic eruptions, as there is the potential for serious health damage. Checking locally available hazard maps for locations of active volcanoes and their current potential for eruptions is recommended when going to the vicinities of active volcanoes.
Negative Impacts of Volcanic Eruptions

The negative impacts of volcanic eruptions to humans can come in several different ways. One comes from cinders, or objects spewed into the air during eruptions. They can disseminate several kilometers from the source of the eruption, and fatally injure people as well as damage cars, houses, and roads. Hide behind big sturdy rocks or buildings to avoid being hit by cinders.

A pyroclastic flow is a stream of rocks, superheated steam, and volcanic ash that flow down the volcano after an eruption. It can reach speeds up to several hundred kilometers per hour and temperatures of several hundred degrees. It is impossible to flee from the path of a pyroclastic flow once it occurs. It is an extremely fearsome phenomenon that can flood, burn, and destroy a wide area regardless of changes in topography. When a pyroclastic flow occurs, you should run away from riverbeds and other routes taken by the flow.

Eruptions also release volcanic gas into the air. Colorless volcanic gas can be difficult to detect as a source of danger. However extreme caution is necessary as it can be potentially toxic and cause damage to your respiratory systems. The worst case scenario is permanent health damage and even death.

Warnings and Advisory Information

To minimize potential damages from volcanic eruptions, the Japan Meteorological Agency closely monitors the activities of 111 active volcanoes throughout Japan and provides real-time volcanic alerts on the monitoring.

Standardized volcanic alert in Japan follows a five-level scale, with 1 being the lowest and 5 the most urgent (please see table below). As active volcanic activities are observed, the alerts will be issued on TV and over the Internet. It is advised that travelers take the actions corresponding to the warnings in order to avoid dangers from lapses in personal decision-making.

Volcanic Warning System (for volcanoes where volcanic alert levels are applied)

Emergency Warning (Target area Residential areas and non-residential areas nearer the crater, Levels5, Keyword Evacuate)
Expected volcanic activity: Eruption or imminent eruption that may cause serious damage in residential areas and non-residential areas nearer the crater.
Action to be taken by residents: Evacuate from the danger zone. (Target areas and evacuation measures are determined in line with current volcanic activity.)

Emergency Warning (Target area Residential areas and non-residential areas nearer the crater, Levels4, Keyword Prepare to evacuate)
Expected volcanic activity: Possibility or increased possibility of eruption that may cause serious damage in residential areas and non-residential areas nearer the crater.
Action to be taken by residents: Prepare to evacuate from alert areas. Have disabled people evacuate. (Target areas and evacuation measures are determined in line with current volcanic activity.)

Warning (Target area Non-residential areas near the crater, Levels3, Keyword Do not approach the volcano)
Expected volcanic activity: Eruption or possibility of eruption that may severely affect places near residential areas (possible threat to life in such areas).
Action to be taken by residents: Stand by and pay attention to changes in volcanic activity. Have disabled people prepare to evacuate in line with current volcanic activity.

Warning(Target area Around the crater, Levels2, Keyword Do not approach the crater)
Expected volcanic activity: Eruption or possibility of eruption that may affect areas near the crater (possible threat to life in such areas).
Action to be taken by residents: No action required.

Forecast(Target area Inside the crater, Levels1, Keyword Potential for increased activity)
Expected volcanic activity:Calm: Possibility of volcanic ash emissions or other related phenomena in the crater (possible threat to life in the crater).
Action to be taken by residents: No action required.

Source: Volcanic Warning System (for volcanoes where volcanic alert levels are applied), the homepage of the Japan Meteorological Agency
http://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/kaisetsu/English/level.html

“The Features of Volcanic Disasters,” e-College (Fire and Disaster Management Agency of the Ministry of Internal Affairs and Communications)
http://open.fdma.go.jp/e-college/study00/kiso/saigai_chishiki/kazan/03/index.html

5. Extreme Heat and Other Disasters

Extreme Heat and Heatstroke - Description

Extreme Heat days denote days of extremely high temperatures accompanied by high humidity levels. Ongoing climate change has made it possible for temperature to rise above 40 °C in Japan. Extreme heat threatens travelers venturing outside buildings with heatstroke and dehydration. From the 4th Wednesday of April to the 4th Wednesday of October, Japan Meteorological Agency issues “high-temperature advisory” whenever the temperature of any locale reaches 35 °C (*1) to call for caution of heatstroke. Travelers are advised to check weather forecasts in regions where they are traveling, in order to avoid excessively high temperatures.
*1 Some areas may use a figure other than 35 °C.

Symptoms of Heatstroke and Countermeasures

Heatstroke occurs when the body suffers from an imbalance of water and salts (including sodium) due to high temperature and humidity. The imbalance makes it impossible for the body to adjust its temperature. This causes an array of different symptoms, including an increase in body temperature, dizziness, fatigue, and in more extreme cases, spasms and hallucinations. Heatstroke can occur even indoors if high room temperature and humidity prevent excess heat from leaving the body easily.

Those suffering from heat stroke should be moved to cooler or shaded space, have their clothing loosened, and laid down. Blow wind directly on the heatstroke victim with air-conditioners or fans, cooling down the body, particularly around the neck, below the armpits, base of their thighs, and other areas with thick blood vessels. If the victim can drink water, help him or her drink gradually. If the victim cannot drink water, cannot move due to excess fatigue, is unconscious, or is showing signs of spasm across the entire body, call an ambulance immediately.

Lightning, Tornadoes, Landslides - Description

Other disasters to be mindful of include lightning, tornadoes, land- and mudslides, among others. Lightning generally strikes tall, protruding objects, but people in open areas, such as a golf course, or under trees sheltering from rains, can be in mortal danger. It is advisable to seek shelter in concrete buildings or vehicles when hearing thunder nearby.

Tornadoes are strong circular winds that are generated by upward-moving airflows accompanying accumulating clouds. Though they can occur any time of the year, tornadoes are most frequently seen in September, during the typhoon season. In their center, tornadoes generate powerful winds that can pick up buildings and billboards from the ground, injuring people with these moving objects. Travelers are advised to enter concrete buildings or underground facilities and wait for the tornado to pass.

Land- and mudslides occur when accumulated sediments on slopes are dislodged by rain and waters, allowing them to rush downhill at devastating speeds. People and buildings near the slopes are washed downhill. If there are any signs of a landslide, travelers should assume its occurrence is imminent and evacuate immediately.
If possible act quickly when it is still possible to safely evacuate, even before you feel in danger. In particular, the elderly and those with physical handicaps should be evacuated in advance.

Source:
“Heatstroke Countermeasures Leaflet,” homepage of the Fire and Disaster Management Agency
https://www.fdma.go.jp/neuter/topics/fieldList9_2/pdf/leaflet.pdf

“Guide for Ambulance Services,” homepage of the Fire and Disaster Management Agency
http://www.fdma.go.jp/html/life/gaikokujin_kyukyusya_guide/pdf/pamphiet_english.pdf（English）

“Types of Tornadoes,” homepage of the Japan Meteorological Agency

https://www.data.jma.go.jp/obd/stats/data/bosai/tornado/

“Actions to be Taken in Response to Dangers from Wind- and Water-Caused Disasters: Supplement,” e-College (Fire and Disaster Management Agency of the Ministry of Internal Affairs and Communications)
http://open.fdma.go.jp/e-college/study00/kiso/saigai_chishiki/fuuzuigai/04_2/index.html

Source: Fire and Disaster Management Agency of the Ministry of Internal Affairs and Communications