{"action_steps":["Find out whether your home, workplace, or regular route is in the tsunami hazard area.","Develop and practice a household evacuation plan.","Learn tsunami warning signs, signals, and what local sirens mean.","If you manage a coastal property or facility, use elevation and flow-through design measures where appropriate.","Do not wait for perfect confirmation if a strong warning or clear natural sign tells you to leave low coastal areas."],"at_risk_groups":["People with barriers to evacuation.","Adults over age 65.","Lower- and middle-income residents who may have fewer resources for relocation or protection.","People near beaches, low-lying coastal areas, tidal flats, and river deltas."],"base_priority_score":5,"historical_examples":["1964 Alaska tsunami that produced 10 to 23 foot wave heights off the North Coast and about 4 feet in the San Francisco Bay area.","2011 Japan tsunami that caused over $100 million in damage in Santa Cruz and two fatalities.","December 5, 2024 offshore Cape Mendocino event; Oakland activated its tsunami siren system, but no local damage was reported."],"key_stats":["Official Priority Risk Index (PRI): 1.7, ranked Low.","The LHMP identifies 22 tsunami events known to have impacted Alameda County/Oakland over 170 years, averaging one every 7.8 years; most were minor with 3 feet or less of runup.","Population exposed: 19,450 people (4.4% of the city population).","Estimated impact: 15,900 displaced households and 573 people needing short-term shelter.","Buildings exposed: 5,071; lifelines exposed: 608.","Total exposed building value: $16,965,465,804; estimated damages: $3,563,926,147."],"locations":["Beaches and low-lying coastal areas.","Tidal flats and river deltas.","Oakland San Francisco Bay Airport.","Rail lines connecting to the Port of Oakland.","Three wastewater treatment plants."],"name":"Tsunami/Seiche","personalization_notes":[],"personalized_what_this_means_for_you":"If you spend time near the shoreline, the airport, port-connected areas, tidal flats, or other low-lying water edges, you should know your evacuation route and warning signals.","priority_reason":"The LHMP ranks tsunami/seiche low because most recorded impacts are minor, but the shoreline exposure is still meaningful. It remains a moderate app priority because a larger event could affect thousands of people, critical facilities, and evacuation routes.","priority_score":5,"real_world_impact":"For most Oakland residents this is a lower-probability hazard, but for shoreline users and workers it can become an urgent evacuation and infrastructure problem.","risk_level":"Low","slug":"tsunami-seiche","summary":"Tsunami and seiche hazards mainly affect Oakland's shoreline and other low-lying water-adjacent areas. Most events have been minor, but a stronger event could create fast-moving flood and evacuation problems.","top_risks":["Fast shoreline inundation and property damage in low-lying areas.","Difficult evacuation for people with mobility, health, or transportation barriers.","Disruption to airport, rail, wastewater, and port-linked infrastructure.","Large displacement from a bigger coastal event.","Low warning confidence for local events compared with more distant tsunamis."],"what_could_realistically_happen":"A distant or regional tsunami could push water into low shoreline areas, close transportation routes, and force fast evacuations. Larger events could disrupt wastewater plants, rail, and airport operations.","what_this_means_for_you":"If you spend time near the shoreline, the airport, port-connected areas, tidal flats, or other low-lying water edges, you should know your evacuation route and warning signals.","why_this_is_a_real_threat_in_oakland":"Oakland has exposed shoreline infrastructure, low-lying areas, and people who may have trouble evacuating quickly. The LHMP also notes that sea-level rise can make future tsunami impacts worse."}