札幌 地震 震度：知っておきたい情報

Hey guys! Let's talk about something super important, especially if you're living in or planning to visit Sapporo: earthquakes and their intensity (震度 - shindo). Knowing about seismic activity is crucial for safety, and understanding the intensity scale helps us gauge the impact of an earthquake. In this article, we're going to dive deep into everything you need to know about earthquake intensity in Sapporo, from what the Shindo scale means to how Sapporo fares in terms of seismic activity. We'll also cover some essential safety tips that everyone should be aware of. So, buckle up, and let's get informed!

Understanding the Shindo Scale: What Do Those Numbers Mean?

First things first, let's break down the Shindo scale. You often hear about Shindo 5 or Shindo 6 when an earthquake hits Japan. But what does that actually signify? The Shindo scale is Japan's unique way of measuring the intensity of an earthquake at a specific location, focusing on the actual shaking felt by people and the effects on the surrounding environment, rather than the earthquake's magnitude (which measures the energy released at the source). It ranges from 0 to 7, with some levels (4, 5, 6, and 7) being further divided into 'weak' (弱 - yowa) and 'strong' (強 - kyō).

• Shindo 0: Not felt, or only by very sensitive instruments. Basically, nothing anyone would notice.
• Shindo 1: Felt by some people indoors, especially on upper floors of buildings, but often dismissed as something else.
• Shindo 2: Felt by most people indoors. Some may wake up from sleep. Light objects might sway.
• Shindo 3: Felt by almost everyone indoors. Many people are alarmed. Dishes in cupboards may rattle, and unstable objects might fall.
• Shindo 4: Felt by most people outdoors. Many are frightened. Doors may slam, and glassware might break. This is where things start getting serious for a lot of folks.
• Shindo 5-weak: Most people run outdoors in panic. Many dishes are broken, and most unstable objects fall. Some damage to buildings may start to occur.
• Shindo 5-strong: Severe shaking. People are thrown off balance. Considerable damage to buildings, including cracks in walls and damage to infrastructure like roads and pipes.
• Shindo 6-weak: It's difficult to stand or walk. Most buildings suffer significant damage, with many collapsing. Landslides and the collapse of utility poles can occur.
• Shindo 6-strong: Most buildings collapse, and many people are injured or killed. Roads become impassable, and large-scale landslides are common. It's extremely dangerous to be outside.
• Shindo 7: Catastrophic shaking. Almost all buildings collapse, and nothing can be done to prevent damage. The ground itself can liquefy or crack open. This is the most severe level.

It's important to remember that the Shindo intensity can vary greatly even within a relatively small area. The intensity at your exact location depends on factors like the distance from the earthquake's epicenter, the type of soil beneath you (softer soil can amplify shaking), and the type of building you're in. So, while an earthquake might be reported as Shindo 5 in one part of Sapporo, it could be Shindo 4 or Shindo 6 in another. Pretty wild, right?

Sapporo's Seismic Landscape: Is It a High-Risk Zone?

Now, let's talk about Sapporo and earthquakes. Hokkaido, the island where Sapporo is located, is known for its seismic activity. Why? Because it sits in a complex tectonic setting, where several major tectonic plates converge. The Pacific Plate, the North American Plate, and the Eurasian Plate all interact in this region, leading to frequent geological stresses that can result in earthquakes. While Hokkaido experiences numerous earthquakes each year, Sapporo itself is generally considered to be at a lower risk for major, devastating earthquakes compared to some other parts of Japan, like the Kanto region (which includes Tokyo) or the Tokai region.

However, this doesn't mean Sapporo is immune. The city can and does experience earthquakes originating from offshore or from faults within Hokkaido. Major earthquakes that have affected Hokkaido in the past, such as the 2018 Hokkaido Eastern Iburi earthquake (which caused significant damage and shaking up to Shindo 7 in parts of Iburi Subprefecture, affecting Sapporo with Shindo 5-weak), serve as a stark reminder that seismic events are a reality for Sapporo residents. The intensity experienced in Sapporo during such events depends heavily on the epicenter's location and the depth of the earthquake. Earthquakes occurring further away might register lower intensities in Sapporo, while those closer or directly beneath Hokkaido could lead to stronger shaking.

It's also worth noting that aftershocks can be a concern following a major earthquake. These are smaller earthquakes that occur in the same area after a larger one has finished. While they are typically less intense, they can still cause further damage to already weakened structures and cause additional anxiety. Preparedness is key, regardless of the perceived risk level. Understanding the history of seismic activity in the region and staying informed about current seismic monitoring is the best way to approach the topic. The Japan Meteorological Agency (JMA) provides real-time information on earthquakes, which is an invaluable resource for residents and visitors alike. So, while Sapporo might not be on the front lines of Japan's most frequent earthquake zones, taking precautions and being informed is always the wisest approach. Remember, preparedness saves lives, and knowing the potential risks is the first step.

Safety First: What to Do Before, During, and After an Earthquake

Alright guys, knowing about earthquakes is one thing, but knowing how to react is another. Being prepared for an earthquake in Sapporo, or anywhere else for that matter, can significantly reduce the risk of injury and damage. Let's break down what you should do in three key phases: before, during, and after an earthquake.

Before an Earthquake: Preparation is Key!

This is arguably the most important phase. Proactive earthquake preparedness in Sapporo can make a world of difference.

• Secure your home: This is a big one. In your home, make sure heavy furniture like bookshelves, cabinets, and TVs are securely anchored to the walls. Use earthquake straps or brackets. Think about what could fall and hit you or block your exit. Also, secure hanging objects like ceiling fans or light fixtures. If you live in an older building, check if it meets current earthquake-resistance standards.
• Create an emergency kit: This is your lifeline if services are disrupted. Include essentials like bottled water (at least one gallon per person per day for several days), non-perishable food, a first-aid kit, a flashlight with extra batteries, a portable radio, medications, sanitation supplies, a multi-tool, and copies of important documents. Don't forget cash, as ATMs might not work. A whistle can be useful to signal for help.
• Develop a family emergency plan: Discuss with your family members what to do during and after an earthquake. Identify safe spots in each room (under a sturdy table or desk, or against an interior wall away from windows). Designate an out-of-state contact person who everyone can check in with, as local phone lines might be jammed. Know how to shut off gas and water mains if necessary – but only if you know how and it's safe to do so.
• Know your surroundings: If you're in a public place, identify potential hazards like heavy objects that could fall, and know the nearest exits. If you're in a high-rise building, be aware of specific safety guidelines for those locations.
• Practice: Have regular earthquake drills. Knowing what to do instinctively can save precious seconds during a real event.

During an Earthquake: Drop, Cover, Hold On!

When the shaking starts, remember the golden rule: "Drop, Cover, Hold On!" This is the most effective way to protect yourself from falling debris and injuries.

• Drop: Immediately drop down onto your hands and knees. This position protects you from falling but still allows you to move if necessary.
• Cover: Cover your head and neck with your arms. If you can, crawl under a sturdy table or desk for added protection. If there’s no table nearby, crawl next to an interior wall, away from windows, mirrors, or heavy furniture that could fall.
• Hold On: If you are under a table or desk, hold on to one of its legs with one hand. Be prepared to move with it if it shifts. Continue holding on until the shaking stops.

If you are in bed: Stay there and cover your head and neck with a pillow. You are less likely to be injured by falling debris if you stay in bed.

If you are outdoors: Move to an open area away from buildings, streetlights, and utility wires. Drop to the ground and stay there until the shaking stops.

If you are in a vehicle: Pull over to a safe location, stop the car, and stay inside with your seatbelt fastened. Avoid stopping under bridges, overpasses, or power lines. Once the shaking stops, proceed cautiously, listening to your car radio for emergency updates.

If you are in a crowded public place: Do not rush for the exits. Drop, Cover, Hold On, and wait for the shaking to stop. Be aware of falling debris and people around you.

Remember, stay calm. Panic can lead to poor decisions. The shaking usually lasts only for a minute or two, but its effects can be long-lasting if you're not prepared.

After an Earthquake: Assess and Respond

Once the shaking has stopped, it's time to assess the situation and act responsibly. Post-earthquake safety in Sapporo requires a calm and methodical approach.

• Check for injuries: Check yourself and others for injuries. Administer first aid if necessary, but do not move seriously injured persons unless they are in immediate danger.
• Check for hazards: Look for any immediate dangers like gas leaks (if you smell gas or hear a hissing sound, open a window and leave the building immediately, then shut off the main gas valve if you can safely do so), electrical damage, or structural damage to your home. If you suspect a gas leak, do not turn on lights, use matches, or operate any electrical switches or appliances, as this could ignite the gas.
• Be prepared for aftershocks: Aftershocks can occur minutes, days, or even weeks after the main earthquake. Continue to practice "Drop, Cover, Hold On" if shaking resumes.
• Listen to authorities: Use your battery-powered radio or check your phone for official information and instructions from emergency services. Follow their guidance regarding evacuation or shelter-in-place orders.
• Conserve resources: If services like water or electricity are out, use your emergency supplies wisely.
• Help your neighbors: If you are able, check on your neighbors, especially the elderly or those with disabilities.
• Stay informed: Keep updated on the situation through reliable news sources. Avoid spreading rumors.

By understanding the Shindo scale, Sapporo's seismic context, and implementing these safety measures, you can significantly improve your safety and that of your loved ones during an earthquake. Stay safe, guys!

Key Takeaways for Sapporo Residents and Visitors

To wrap things up, let's summarize the most crucial points about earthquake preparedness in Sapporo.

• Understand Shindo: Know that the Shindo scale measures shaking intensity, and it can vary greatly by location. Familiarize yourself with the levels and what they mean for safety.
• Sapporo's Risk: While not the highest-risk zone in Japan, Hokkaido and therefore Sapporo are seismically active. Past events show that significant shaking can occur.
• Prepare Your Home: Secure heavy furniture and objects to prevent them from falling during shaking.
• Build an Emergency Kit: Have essential supplies ready for potential disruptions to services.
• Have a Plan: Discuss earthquake procedures with your family and know your safe spots and evacuation routes.
• Practice "Drop, Cover, Hold On": This is the single most important action to take when shaking begins.
• Stay Informed: Follow official news and emergency alerts from reliable sources.

Being prepared isn't about living in fear; it's about being empowered. By taking these steps, you're not just protecting yourself but also contributing to a safer community in Sapporo. Remember, knowledge and preparation are your best allies when it comes to natural disasters. Stay safe and informed, everyone!