家族通信計画の作成

Why Phones May Not Work After an Earthquake

緊急連絡計画地震後に家族間で連絡を取り合うための事前計画で、遠隔地の連絡先・集合場所・代替の連絡手段などを含む。 infrastructure is one of the first systems to become overwhelmed after a major earthquake. Within seconds of a large event, cell towers serving the affected area are flooded with calls from millions of people attempting to reach family members simultaneously. Network congestion causes calls to fail with busy signals or "all circuits are busy" recordings — not because the towers are damaged, but because they are being overwhelmed by demand that exceeds their engineered capacity by factors of ten or more.

The communication failure following the 1994 Northridge earthquake in Los Angeles lasted approximately four hours for voice calls on most carriers. After the 2011 Tōhoku earthquake in Japan — with far more robust telecommunications infrastructure — cellular voice service was unavailable in parts of the affected area for several days. Planning that assumes phone calls will be available is unreliable; planning that treats phone calls as a bonus capability rather than a guaranteed resource is far more robust.

Text messages have significantly higher delivery rates than voice calls during post-earthquake congestion because they use network resources more efficiently. A text message requires only a brief channel allocation rather than a sustained connection. SMS messages will often queue and deliver when network capacity temporarily increases even if voice calls continue to fail. Teach all household members to send texts to the out-of-area contact first, and to reserve repeated calling attempts for urgent medical situations. Social media platform safety check features (Facebook Safety Check, Google Person Finder) provide additional location confirmation tools that route through internet infrastructure rather than telephone networks.

Out-of-Area Emergency Contact Strategy

The out-of-area contact strategy works because call traffic to areas outside the affected region is not subject to the same congestion as local calls. Calls from an affected area to a distant state flow through the portions of the telephone network that are not overwhelmed, making them significantly more likely to complete. The out-of-area contact then becomes the information hub: collecting location information from multiple family members and relaying it to those who cannot reach each other directly.

Select your out-of-area contact carefully. This person must be reliably reachable — ideally someone who works regular daytime hours and is unlikely to be traveling at the time of a regional earthquake. They should be calm under pressure and able to record and relay information accurately. Brief them thoroughly on their role: they are not expected to provide advice or emotional support during the initial contact; their job is to record each caller's name, location, and status and convey this information when asked by other family members.

Give the out-of-area contact a written briefing document listing all household members' full names, ages, school or workplace locations, medical needs, and vehicle descriptions. Update this document annually and whenever significant household changes occur. The contact should have this document accessible at home and digitally so they can pull it up immediately when the first call arrives. Include the contact information for local police, fire, and hospital in case family members need assistance that the contact cannot directly provide.

Physical Meeting Points: Primary and Secondary

Physical meeting points are the backbone of a family 緊急連絡計画地震後に家族間で連絡を取り合うための事前計画で、遠隔地の連絡先・集合場所・代替の連絡手段などを含む。 plan because they work without phones, internet, or any other technology. Designate two specific, unambiguous locations that every family member can navigate to independently: a primary point within one or two blocks of home for use when the neighborhood is accessible, and a secondary point farther away — typically near the school or workplace of the most distant household member — for use when the neighborhood is blocked or inaccessible.

The primary meeting point should be immediately visible from the street, accessible by foot without crossing major roads, and far enough from the building that it is outside the debris fall zone. A neighbor's yard, a corner street sign, or a park bench at the end of the street are suitable examples. The exact location should be unambiguous: "the red mailbox at the corner of Elm and 4th" rather than "near the park." Practice walking to the primary meeting point with all household members, including children, until everyone can navigate there without prompting.

The secondary meeting point must be chosen with an understanding of the travel scenario: if roads are blocked, can family members walk there? How long would it take on foot? Is there a clear walking route that avoids bridges and underpasses? For families with school-age children, the secondary meeting point is often the school itself; parents should know the school's release and family reunification policy for earthquake scenarios before an event occurs. Many schools will hold children until a parent or designated authorized adult arrives in person; understanding this policy prevents parental panic when children cannot be immediately reached by phone.

Digital Backup: Apps and Social Media

In addition to the out-of-area contact phone strategy, digital tools provide complementary emergency communication channels that can function during periods when voice calls fail but internet connectivity remains partially functional. The Red Cross Emergency app provides shelter locations, safety tips, and a "I'm Safe" notification feature that posts to social media automatically. FEMA's app provides real-time alerts and weather warnings. Google's Person Finder database is activated following major disasters and allows both reporting and searching for person status.

Establish family agreements about which digital platforms will be used for status updates after an earthquake. "I will post to [Family Group Chat name] and also check in on [platform] with the hashtag [family-specific code word]" provides a structured protocol that all family members can follow without coordination during the event. Choose platforms with broad penetration and reliability over niche tools; after a major disaster, the most widely used platforms receive the fastest technical support for any outages.

Pre-draft a status template that any family member can send: "I am [name], I am [safe/injured/I need help], I am at [location], [time]. Contact [out-of-area contact] for info." This template eliminates the cognitive load of composing a message under acute stress and ensures that status updates contain all the information other family members need to assess the situation.

Practicing Your Communication Plan

A communication plan that has never been practiced will not function smoothly under the cognitive and emotional load of a real earthquake. Conduct a tabletop drill twice per year: sit down as a family, announce "an earthquake has just occurred," and walk through the full communication sequence — who sends what to whom, in what order, and what happens if the first channel doesn't work. This exercise reveals gaps (a child who doesn't know the out-of-area contact's number, a communication app that requires an update) before they become crises.

Conduct an unannounced practical drill at least once per year: send a text to all family members simultaneously announcing a hypothetical earthquake and asking them to "report" to the out-of-area contact within five minutes using the agreed protocol. This tests whether the protocol is internalized or merely known intellectually — two very different levels of preparedness. The drill also tests the out-of-area contact's ability to execute their hub role, which should be practiced separately with that person.

Update the communication plan after every significant household change: a child starting at a new school, a family member changing jobs, a new person added to the household, or a change in the out-of-area contact's availability. A plan that is accurate reflects current household reality; a plan with outdated information can direct family members to wrong locations or wrong contacts, compounding disorientation during an already chaotic event. Link the annual update to a fixed calendar event — a birthday, a holiday, or the October ShakeOut drill — to ensure it happens consistently.