How to Prepare for Earthquake Aftershocks: Your Complete Safety Guide

The ground has stopped shaking after a major earthquake, but your emergency response shouldn’t end there. Aftershocks—smaller earthquakes that follow the main shock—can strike minutes, days, or even months after the initial quake, causing additional damage to already-weakened structures and creating new hazards. According to the United States Geological Survey (USGS), large earthquakes can generate aftershocks that continue for years, with the risk being highest immediately following the main event. Understanding how to prepare for these secondary tremors is crucial for keeping yourself and your loved ones safe during this extended period of vulnerability.

At Batten Home Security, we’ve found that many families focus their earthquake preparedness on the initial event but overlook the critical need for aftershock planning. This comprehensive guide will walk you through practical steps to stay safe during the uncertain aftermath of a major earthquake, when infrastructure may be compromised and emergency services stretched thin.

Understanding Earthquake Aftershocks: What to Expect

Aftershocks are smaller earthquakes that occur in the same general area as the main shock, caused by the crust adjusting to the changes in stress created by the main quake. According to seismologists at the USGS, aftershocks typically follow a predictable pattern: they’re most frequent immediately after the main quake and gradually decrease in frequency and magnitude over time. However, this doesn’t mean they’re harmless—aftershocks can be powerful enough to collapse structures already weakened by the main earthquake, particularly if that quake was significant in magnitude.

The rule of thumb among emergency management professionals is that aftershocks can reach about one magnitude less than the main shock. For instance, if you experience a magnitude 7.0 earthquake, you should be prepared for aftershocks up to magnitude 6.0, which can still cause significant damage. In regions with complex fault systems like California, Japan, or New Zealand, aftershock sequences can be particularly prolonged and unpredictable.

Immediate Safety Actions Following the Main Earthquake

The period immediately following a major earthquake is critical for aftershock preparedness. During this time, buildings and infrastructure may be compromised, creating dangerous conditions if additional shaking occurs. Based on guidelines from FEMA and the experiences of communities we’ve worked with in seismically active regions, these first steps should be taken as soon as the initial shaking stops and before aftershocks begin:

Check for injuries: Attend to yourself first, then help others. Apply first aid for minor injuries and seek emergency assistance for serious conditions if services are available.
Evacuate damaged buildings: If you notice structural damage like cracked walls, shifted foundations, or broken utility lines, exit the building immediately and move to an open area away from structures, trees, and power lines.
Turn off utilities: If you smell gas or suspect a leak, turn off the main gas valve. Also consider shutting off electricity and water, especially if lines may be damaged.
Put on protective gear: Sturdy shoes, long pants, long-sleeved shirts, work gloves, and a hard hat or bicycle helmet can protect against falling debris during aftershocks.
Check your surroundings: Look for hazards like broken glass, fallen objects, damaged stairs, or unstable furniture that could cause injury during an aftershock.
Account for all household members: Establish a meeting point and make sure everyone knows where to gather if separated during an aftershock.

Creating a Safe Zone for the Aftershock Period

After a significant earthquake, you may need to identify both indoor and outdoor safe zones where you can quickly take cover during aftershocks. The Red Cross and emergency management experts recommend setting up these areas based on structural integrity and distance from potential hazards. Many of the families we’ve assisted with emergency planning find that dedicating specific “aftershock safe zones” provides both practical protection and peace of mind during the stressful post-earthquake period.

Indoor Safe Zones

If your home has been inspected and deemed safe to occupy after the main quake, designate specific areas within your home as aftershock safe zones. These should be places where you can quickly implement the “Drop, Cover, and Hold On” technique when aftershocks strike.

Identify sturdy furniture: Look for solid tables or desks that can withstand falling debris. Position these away from windows, exterior walls, and heavy objects that could fall.
Clear pathways: Ensure routes to your safe zones are free of obstacles so you can reach them quickly when shaking begins.
Avoid dangerous areas: Stay away from kitchens with heavy appliances, rooms with large hanging fixtures, or spaces near chimneys that could collapse.
Consider structural integrity: Interior walls and doorways in the center of the building are typically more stable than exterior walls.
Keep safety supplies nearby: Store dust masks, flashlights, and a whistle in your designated safe zones for quick access.

Outdoor Safe Zones

If your home is damaged or you’re concerned about its structural integrity, you may need to stay outdoors until professional assessment is complete. According to emergency management experts at FEMA, properly selected outdoor areas can provide safer alternatives when buildings are compromised.

Find open spaces: Seek areas away from buildings, utility lines, trees, and other structures that could fall.
Set up temporary shelter: If available, set up a tent or other temporary shelter in your identified safe zone. Position it away from potential hazards.
Create boundary markers: Use rope, tape, or other markers to identify your safe zone boundaries for all family members.
Consider terrain: Avoid areas near steep slopes that could experience landslides during aftershocks.
Plan for weather: Your outdoor safe zone should provide protection from sun, wind, and rain if possible.

Securing Your Home Against Aftershock Damage

Aftershocks can cause additional damage to structures already weakened by the main earthquake. According to structural engineers who specialize in seismic safety, taking steps to secure and stabilize your environment can significantly reduce the risk of injury and property damage during these secondary tremors. Based on post-earthquake assessments we’ve reviewed from regions like California and Japan, these stabilization measures have proven most effective in preventing cascading damage from aftershocks.

Immediate Stabilization Measures

Secure heavy furniture: Anchor bookshelves, cabinets, and tall furniture to wall studs using flexible straps or L-brackets.
Move heavy objects to lower shelves: Relocate heavy items to floor level to prevent them from falling during aftershocks.
Secure hanging objects: Remove or securely fasten light fixtures, ceiling fans, and decorative items that could fall.
Brace damaged components: If safe to do so, use lumber to brace damaged walls or support beams that show signs of stress.
Secure water heaters: Strap water heaters to wall studs using heavy-duty metal strapping to prevent gas leaks or water damage.
Address cabinet doors: Install latches on cabinet doors to prevent contents from spilling during aftershocks.

Professional Assessment and Repairs

For homes that have experienced moderate to severe damage in the main earthquake, professional assessment becomes critical before aftershocks cause additional structural failures. The American Society of Civil Engineers recommends having qualified professionals evaluate your home’s condition as soon as possible after a significant earthquake.

Structural inspection: Have a structural engineer assess your home’s foundation, load-bearing walls, and roof connections.
Chimney evaluation: Chimneys are particularly vulnerable to earthquake damage and can pose serious hazards during aftershocks.
Utility system checks: Have gas lines, electrical systems, and plumbing inspected for damage that could worsen during aftershocks.
Document damage: Take photos and notes of all earthquake damage for insurance claims and to track any progression during aftershocks.
Prioritize repairs: Address structural issues before cosmetic damage, focusing on elements that could fail during aftershocks.

Building an Aftershock Emergency Kit

Standard emergency kits should be enhanced for the specific challenges of an aftershock sequence. According to emergency response coordinators who’ve managed major earthquake recovery efforts, the post-earthquake period often involves disrupted supply chains, limited access to utilities, and reduced emergency services—all of which can be further complicated by ongoing aftershocks. We typically recommend families in seismic zones prepare supplies that can sustain them for at least two weeks, rather than the standard three days, specifically to address the extended disruption that aftershock sequences can cause.

Essential Supplies for Aftershock Preparedness

Water: Store at least one gallon per person per day for two weeks. Consider water purification tablets or filters as backup.
Food: Stock non-perishable, ready-to-eat foods that don’t require cooking, refrigeration, or extensive water.
Medication: Maintain a two-week supply of prescription medications and basic over-the-counter remedies.
First aid supplies: Include bandages, antiseptic, pain relievers, and any specific items needed for family members’ medical conditions.
Lighting: Pack flashlights, headlamps, and light sticks with extra batteries. Solar-powered options reduce dependency on battery supplies.
Communication tools: Include a hand-crank or battery-powered radio, whistle, and portable phone charger.
Personal protective equipment: Store dust masks, work gloves, sturdy shoes, and eye protection for navigating damaged areas.
Sanitation items: Pack toilet paper, hand sanitizer, personal hygiene products, and heavy-duty garbage bags.
Tools: Include a multi-tool, wrench for turning off utilities, duct tape, and plastic sheeting for emergency repairs.
Comfort items: Consider stress-relief items like books, games, or comfort objects for children to help manage anxiety during aftershocks.

For a complete emergency preparation kit, we recommend reviewing FEMA’s comprehensive checklist and adapting it to your family’s specific needs and regional risks.

Creating a Family Aftershock Response Plan

Families who successfully navigate the aftershock period typically have clear, practiced response plans that all household members understand. According to psychological research on disaster resilience, having predetermined roles and actions reduces decision fatigue and panic during emergencies. Based on feedback from community preparedness programs, we’ve found that families who develop and practice their aftershock response plans report feeling significantly more confident in their ability to stay safe during extended seismic events.

Key Components of an Aftershock Response Plan

Drop, Cover, and Hold On refresher: Ensure all family members know to immediately drop to the ground, take cover under sturdy furniture, and hold on until the shaking stops.
Evacuation routes: Identify multiple ways to exit your home and neighborhood, accounting for potential road damage or building collapses.
Meeting locations: Designate primary and secondary meeting points—one near your home and another outside your neighborhood if evacuation is necessary.
Communication protocol: Establish how family members will contact each other if separated. Consider text messaging as it may work when phone calls don’t.
Out-of-area contact: Designate someone outside your region as a central point of contact, as local communications may be overwhelmed.
Role assignments: Assign specific responsibilities to family members, such as grabbing the emergency kit, assisting children or pets, or checking utilities.
Special needs considerations: Make specific plans for family members with disabilities, medical conditions, or mobility issues.
Pet plan: Include provisions for pet safety, including carriers, food, and identification.

Practicing Your Aftershock Response

Emergency management experts emphasize that plans are only effective if regularly practiced and updated. The Great ShakeOut earthquake drills, conducted annually in many seismic regions, provide an excellent framework for family practice sessions.

Schedule regular drills: Practice your aftershock response quarterly, including Drop, Cover, and Hold On techniques.
Run through scenarios: Practice responding to aftershocks occurring at different times of day and in different locations.
Time your response: Measure how quickly your family can gather at meeting points and access emergency supplies.
Test communication plans: Practice your family communication protocol, including reaching your out-of-area contact.
Review and refine: After each practice session, discuss what worked well and what could be improved.
Update as needed: Revise your plan as family circumstances change or as you identify new considerations.

Monitoring Aftershock Activity and Warnings

Staying informed about aftershock patterns can help you make safer decisions during the post-earthquake period. Seismologists use sophisticated monitoring systems to track aftershock sequences and provide forecasts about their likely frequency and magnitude. According to the USGS, while individual aftershocks cannot be predicted with precision, the overall pattern and probability of aftershocks can be estimated based on statistical models and real-time seismic data.

Tools and Resources for Aftershock Monitoring

USGS Earthquake Notification Service: Sign up for alerts about significant seismic activity in your area.
Earthquake apps: Download applications like MyShake, QuakeFeed, or the FEMA app that provide real-time earthquake information.
Local emergency management websites: Check your regional emergency management agency’s website for area-specific aftershock information.
NOAA Weather Radio: These radios broadcast emergency alerts and can provide aftershock warnings even when other communications fail.
Social media accounts: Follow official accounts of geological surveys and emergency management agencies for updates.
Community alert systems: Register for local text or email alert systems that distribute emergency information.

Understanding Aftershock Forecasts

Aftershock forecasts typically provide probabilities rather than definitive predictions. Learning to interpret these forecasts can help you make informed decisions about when to exercise extra caution or temporarily evacuate damaged structures.

Probability statements: Aftershock forecasts often state the likelihood of earthquakes of various magnitudes occurring within specific time periods.
Aftershock maps: These show the distribution of aftershocks and can help identify which areas are experiencing the most activity.
Decay curves: These graphs show how aftershock frequency typically decreases over time following the main shock.
Magnitude comparisons: Pay attention to the relative size of aftershocks compared to the main earthquake.
Sequence duration estimates: Some forecasts include estimates of how long the aftershock sequence might continue.

Special Considerations for Vulnerable Populations

Certain groups face unique challenges during aftershock sequences that require additional planning and resources. According to studies on disaster vulnerability, factors such as age, disability, health conditions, and socioeconomic status can significantly impact a person’s ability to respond effectively to ongoing seismic threats. Based on guidance from organizations like the American Red Cross and disability advocacy groups, these considerations should be incorporated into aftershock preparedness plans for vulnerable community members.

Planning for Children

Age-appropriate education: Teach children about aftershocks in simple, non-frightening terms appropriate for their age.
Practice drills: Regularly practice Drop, Cover, and Hold On with children so the response becomes automatic.
Comfort items: Include favorite toys, books, or blankets in emergency kits to provide comfort during stressful situations.
Identification: Ensure children carry or wear identification with contact information in case of separation.
School coordination: Understand and coordinate with your children’s school earthquake and aftershock procedures.
Emotional support: Prepare to address fears and anxiety that children may experience during extended aftershock sequences.

Planning for Seniors and People with Disabilities

Mobility considerations: Create clear pathways to safe zones and ensure assistive devices like canes or walkers are readily available.
Medication management: Maintain an updated list of medications and ensure a minimum two-week supply is accessible.
Medical equipment: Have backup power sources for essential medical equipment that requires electricity.
Support network: Establish a support network of neighbors, friends, or family who can check on vulnerable individuals after an earthquake.
Evacuation assistance: Create a plan for evacuation assistance if needed, including who will help and what specific assistance is required.
Communication alternatives: Ensure multiple methods of communication are available for those with hearing, vision, or speech impairments.

Managing Psychological Impacts of Prolonged Aftershock Sequences

The psychological toll of living through extended aftershock sequences can be significant. According to mental health researchers who’ve studied post-earthquake communities, the unpredictability of aftershocks can lead to heightened anxiety, sleep disturbances, and symptoms of post-traumatic stress. Mental health professionals who specialize in disaster psychology emphasize that acknowledging and addressing these psychological impacts is just as important as physical safety measures.

Recognizing Stress Responses

Physical symptoms: Headaches, stomach problems, changes in appetite, and difficulty sleeping.
Emotional responses: Anxiety, fear, irritability, sadness, or emotional numbness.
Cognitive effects: Difficulty concentrating, indecisiveness, or intrusive thoughts about the earthquake.
Behavioral changes: Increased use of alcohol or substances, withdrawal from social activities, or hypervigilance.
Child-specific reactions: Regression to younger behaviors, clinginess, or acting out.

Coping Strategies for Aftershock Anxiety

Establish routines: Create and maintain daily routines to restore a sense of normalcy and control.
Practice relaxation techniques: Use deep breathing, meditation, or progressive muscle relaxation to manage anxiety.
Limit media exposure: Stay informed but avoid constant monitoring of aftershock news and social media.
Connect with others: Share experiences and concerns with trusted friends, family, or community members.
Focus on what you can control: Channel energy into concrete preparedness actions rather than worrying about unpredictable events.
Seek professional help: Don’t hesitate to contact mental health professionals if stress becomes overwhelming.
Practice self-care: Prioritize adequate sleep, healthy eating, physical activity, and enjoyable activities.
Help others: Assisting neighbors or participating in community recovery efforts can provide a sense of purpose and control.

If you’re experiencing severe anxiety or symptoms of post-traumatic stress that interfere with daily functioning, contact the Disaster Distress Helpline at 1-800-985-5990 or text “TalkWithUs” to 66746 for crisis counseling and support.

Returning Home After Evacuation: Safety Assessment

If you’ve evacuated your home due to earthquake damage, determining when it’s safe to return requires careful assessment, especially when aftershocks continue. According to structural engineers and building safety inspectors who work in post-earthquake environments, premature re-entry into damaged structures during an active aftershock sequence can put lives at risk. Based on protocols developed by building departments in seismically active regions, these steps should be followed before returning to a home after a significant earthquake.

Professional Inspection Guidelines

Official clearance: Wait for authorities to declare your area safe for re-entry after conducting area-wide safety assessments.
Building inspection: Have your home professionally inspected by a structural engineer or qualified building inspector.
Inspection documentation: Obtain written documentation of the inspection results, including any repairs needed before safe occupancy.
Utility inspection: Have gas, electrical, and water systems inspected by qualified professionals before turning them back on.
Foundation assessment: Pay particular attention to foundation integrity, as this is critical for withstanding aftershocks.
Chimney evaluation: Have chimneys thoroughly inspected, as they’re particularly vulnerable to earthquake damage and aftershocks.

Self-Assessment Safety Checks

While professional inspection is ideal, in some situations you may need to conduct an initial assessment yourself before professionals are available. Exercise extreme caution and err on the side of safety.

Exterior inspection: Before entering, check for structural damage like leaning walls, shifted foundations, or large cracks.
Hazard identification: Look for downed power lines, gas leaks, or water line breaks near your home.
Cautious entry: If the exterior appears safe, enter briefly and cautiously to assess interior damage.
Structural warning signs: Look for sagging ceilings, separated walls, or stairs pulled away from walls.
Utility checks: Check for broken pipes, gas smells, or electrical system damage.
Exit plan: Always maintain a clear exit path and be prepared to leave quickly if an aftershock occurs.

Community Resources and Support Systems

Communities that recover most effectively from earthquakes and their aftershocks typically have strong support networks and resource-sharing systems in place. According to disaster recovery experts, connecting with community resources not only provides practical assistance but also contributes to psychological resilience during extended recovery periods. Based on successful community response models from regions like New Zealand, Japan, and California, these community connections can be vital during the aftershock period.

Local Emergency Services and Information Sources

Emergency management offices: Contact your local emergency management department for area-specific guidance and resources.
Community emergency response teams (CERT): Connect with trained CERT volunteers who can provide neighborhood assistance.
Red Cross and other relief organizations: These organizations often establish shelters, distribute supplies, and provide recovery assistance.
Local government websites and social media: Follow official channels for updates on aftershocks, safety assessments, and resource availability.
Utility companies: Contact information for reporting outages and getting service restoration updates.
211 information line: In many areas, dialing 211 connects you to information about local disaster services.

Neighborhood Support Networks

Neighborhood watch groups: These existing networks can be activated for earthquake recovery support.
Community gathering points: Identify locations where neighbors can share information and resources.
Skill sharing: Connect with neighbors who have useful skills like medical training, construction experience, or counseling abilities.
Resource pooling: Organize systems to share generators, tools, water, or other limited resources.
Check-in systems: Establish regular check-ins for vulnerable community members during the aftershock period.
Childcare cooperation: Create cooperative childcare arrangements to allow parents to handle recovery tasks.

Long-term Planning for Future Earthquake Events

Experiencing an earthquake and its aftershocks provides valuable insights that can improve your preparedness for future seismic events. According to emergency management experts, the recovery period is an ideal time to evaluate what worked well in your preparedness plan and what needs improvement. Based on feedback from communities that have experienced major earthquakes, these long-term planning considerations can significantly enhance resilience for future events.

Home Improvements for Seismic Safety

Structural retrofitting: Consider seismic retrofitting options like foundation bolting, cripple wall bracing, or shear wall installation.
Furniture anchoring: Permanently secure tall furniture, appliances, and heavy objects to prevent tipping.
Flexible utility connections: Install flexible gas and water line connectors that can withstand seismic movement.
Automatic gas shut-off valves: Consider installing valves that automatically stop gas flow during earthquakes.
Cabinet latches: Install earthquake-resistant latches on cabinets containing valuable or hazardous items.
Strategic furniture placement: Rearrange living spaces to keep heavy furniture away from beds and common sitting areas.

Enhanced Emergency Planning

Expanded emergency supplies: Consider increasing your emergency supplies from the standard three-day recommendation to two weeks or more.
Multiple kit locations: Store emergency supplies in multiple locations, including your home, workplace, and vehicle.
Documentation protection: Store important documents in waterproof, portable containers or create digital backups.
Insurance review: Evaluate your earthquake insurance coverage and consider adjustments based on your experience.
Skills development: Take courses in first aid, CERT training, or basic structural assessment to better prepare for future events.
Community involvement: Participate in local emergency planning committees or neighborhood preparedness groups.

Conclusion: Building Resilience Through Preparation

Preparing for earthquake aftershocks requires a comprehensive approach that addresses physical safety, structural integrity, resource management, and psychological wellbeing. By understanding the nature of aftershocks and taking proactive steps to prepare for them, you can significantly reduce the risks they pose to you and your loved ones. Remember that aftershock preparedness isn’t just about surviving the immediate aftermath—it’s about creating systems and practices that support recovery and resilience throughout the extended seismic sequence.

The most effective preparedness strategies combine practical safety measures with community connection and emotional support. By implementing the recommendations in this guide, you’ll be better equipped to navigate the challenges of earthquake aftershocks with confidence and resilience.

For additional support with your emergency preparedness needs, Batten Home Security offers expert-recommended tools and resources designed to help families stay safe during all types of emergencies, including earthquakes and their aftershocks. Browse our emergency preparation products to ensure your home and family are protected when natural disasters strike.

Sources used for this article:

Earthquake Aftershocks, https://www.usgs.gov/faqs/what-are-aftershocks-foreshocks-and-earthquake-swarms

FEMA Earthquake Safety Checklist, https://www.fema.gov/sites/default/files/2020-07/fema_earthquake-safety-at-home_p-530.pdf

The Great ShakeOut Earthquake Drills, https://www.shakeout.org/

Psychological First Aid for Disaster Survivors, https://www.samhsa.gov/dtac/disaster-survivors