Earthquakes

Tectonic earthquakes occur when stress accumulates in rock masses along fault lines. When the stress exceeds the strength of the rocks, it causes sudden fracturing and slips. The Moment Magnitude Scale (MMS) measures earthquakes from magnitude 1 to magnitude 9+. Earthquakes measuring at magnitude 1 are only detected with a seismograph, and those measuring magnitude 9 and above cause near total destruction of all buildings and infrastructure. The depth at which the earthquake occurs also determines how destructive it is; shallow earthquakes cause more damage than deeper ones. 

Earthquakes that measure at magnitudes above 4 or 5 can cause liquefaction, which happens when loosely packed, waterlogged soil and sediment fail to support weight once the ground starts shaking, turning the ground into the consistency of quicksand. Liquefaction is responsible for much of the damage earthquakes cause when the buildings and infrastructure that rest on top of the soil collapse.  

The Pacific Ring of Fire is a string of about 450 active and dormant volcanoes stretching from the southern tip of South America, up the North American coast, down through Japan and into New Zealand.  

The Alpide belt accounts for 17% of the world’s earthquakes, running from Indonesia through the Himalayas, across the Mediterranean and into the Atlantic. In the U.S., several seismic zones carry major risk.  

The San Andreas Fault is the most renown faultline in the U.S., running the length of California. Globally, some of the world’s most populous cities sit on fault lines, including Mexico City, Tokyo, New York City, Mumbai, Delhi, Shanghai, Kolkata and Jakarta. 

Not all earthquakes occur along the edges of tectonic plates. Intraplate earthquakes comprise about 10% of all seismic activity, and occur when tectonic stress accumulates at a weak point in the plate’s interior.  

Volcanoes and earthquakes are interrelated phenomena: earthquakes can occur when magma moves within a volcano, and almost all volcanic eruptions are caused by earthquakes. Additionally, earthquakes that occur under or near the ocean can cause tsunamis. 

Unlike other disasters, earthquakes strike without warning, making them one of the most devastating natural hazards. Scientists are unable to predict earthquakes like they can major storms. Therefore, forecasting relies on historical earthquake data, fault slip rates, GPS measurements of tectonic strain and paleoseismology studies that reveal patterns of past ruptures, which can help guide building codes and emergency preparedness. 

Since 1900, 12 earthquakes have had single-event fatality totals of 50,000 people or more. The most recent was the 2023 Kahramanmaraş earthquake sequence, which killed over 50,000 people in Türkiye and another 8,700 in northwest Syria. 

In addition to children, people living in informal settlements, women, older people, people living with disabilities, and communities with poor infrastructure and limited emergency preparedness are disproportionately affected by earthquakes. Additionally, survivors often become first responders when roads, bridges, airports and communications systems are damaged, leaving many people to provide for their own basic needs until rescue teams and aid groups can arrive. 

Earthquakes cause deaths and injuries, an increase in waterborne and communicable diseases, maternal health risks, a dramatic increase in poverty, and severe consequences to mental health.  

Buildings collapse in seconds, but rebuilding them requires functioning supply chains, skilled labor, materials, permits and financing, all of which are also often affected or disrupted by earthquakes. A hospital cannot be rebuilt if the roads to reach it are broken, and roads cannot be repaired if the required equipment is destroyed. Additionally,  widespread damage to hidden infrastructure, like water systems and sewage treatment plants, creates complex and interconnected challenges that slow progress significantly.   

Often, donor attention wanes long before communities rebuild. Recovery is particularly challenging in lower-middle-income countries and countries where multiple hazards and conflict combine to create a complex humanitarian emergency, such as the 2026 earthquake in Venezuela. Donors may also experience fatigue given the overwhelming needs after such a catastrophic event.   

• Recovery needs will continue long after the headlines fade.
• Support rebuilding work that includes mitigation and risk reduction, make long-term investments to ensure a full recovery, and strengthen preparedness and resilience efforts. 
• As with most disasters and emergencies, unrestricted cash donations to organizations are recommended by disaster experts. Cash allows on-the-ground agencies to direct funds to the most significant areas of need, supports economic recovery and ensures donations can help quickly re-establish access to basic needs.   

We welcome the republication of our content. Please credit the Center for Disaster Philanthropy.   

Photo credit: An M7.2 earthquake struck the southwest of Haiti on Aug. 14, damaging homes and other structures. (Photo courtesy of CORE.)