Scientists have identified three major tsunami risk zones in the U.S.: the **Pacific Northwest**, **East Coast**, and **Gulf Coast**. These are not distant dangers—millions live directly in their path. Tsunamis are caused by underwater earthquakes, landslides, or volcanoes, and can travel at **500 mph**. While deep-sea waves seem calm, “when they hit shallow water… they grow taller and more destructive.”

The **Pacific Northwest** sits on the 700-mile **Cascadia Subduction Zone**. A magnitude 9.0+ quake last struck in **1700**, sending waves across the Pacific to Japan. Scientists warn there’s a **10–14% chance** of another megaquake in the next 50 years. “Ghost forests” and Native stories confirm these deadly waves hit every **300–600 years**.

The **East Coast** faces risks from underwater landslides and Caribbean quakes. The **1755 Lisbon earthquake** sent waves across the Atlantic. Puerto Rico’s **1918** and the Dominican Republic’s **1946** tsunamis killed over **1,600 people** combined.

The **Gulf Coast** is lower-risk but still vulnerable, especially from Caribbean sources. Rising seas and climate change now **amplify tsunami impacts**.

Warning systems offer only **15–20 minutes** notice for local events. “If you feel a strong earthquake near the ocean, RUN.” Scientists race to improve alerts—but your best defense is awareness and quick action.