地震期间在室外做什么:室外安全

Walking or Standing: Move to Open Ground

When shaking begins while you are on foot outdoors, your primary objective is to reach open ground away from all structures, trees, and overhead infrastructure within ten seconds. Move away from buildings, which shed glass, facade tiles, and structural components during 地震烈度根据对人员、建筑物和自然环境的观测影响，衡量特定地点震动强度的指标，随距震中距离增大而降低。 VII or above shaking. A falling facade panel or glass sheet is lethal, and the danger zone extends outward approximately one-quarter of the building's height in all directions.

Once you have cleared the immediate building hazard zone, drop to your hands and knees. Open ground gives you visibility in all directions and eliminates the risk of toppling from loss of balance. Protect your head and neck with your arms and remain on the ground until all shaking has completely stopped. 就地、掩护、抓牢地震震动期间国际公认的防护行动：双手双膝着地，躲到坚固家具下方掩护，并抓牢直至震动停止。 applies outdoors as much as indoors; the "hold" element becomes covering your head with your arms when no table is available.

After shaking stops, assess the ground surface before rising. Cracks in pavement, lateral displacement of sidewalk sections, and wet ground that was previously dry are signs of soil failure. Move away from cracked ground, storm drains, and retaining walls, as subsurface damage may continue to develop in the minutes following the mainshock. Be alert to 余震在同一断层区域内、发生于主震之后的较小地震。余震序列可持续数周至数年，最大余震的震级通常比主震低1.0至1.2级。 sequences, which may begin within seconds of the mainshock ending.

Driving: Pull Over Safely

If you are driving when shaking begins, you may not immediately distinguish earthquake ground motion from a blown tire or road irregularity. The distinguishing characteristic of earthquake shaking is that it affects all vehicles simultaneously and the road surface itself appears to be moving. When you identify earthquake shaking, reduce speed immediately, pull to the right, and stop away from buildings, bridges, overpasses, trees, and power lines.

Stay inside your vehicle during shaking. The vehicle provides a protective cage against most falling debris, and exiting the vehicle during shaking risks being knocked down by ground motion or struck by a moving or skidding vehicle. After shaking stops, check the road ahead before proceeding. Bridge and overpass 次生地震灾害由地震震动引发而非震动本身直接造成的灾害，包括海啸、滑坡、液化、火灾、水坝溃决及化学品泄漏等，其造成的损失往往超过震动本身。 include abutment cracking, deck displacement, and structural failure; do not proceed across a bridge without visual confirmation that the deck is intact.

If you are stopped under an overpass when shaking begins, do not exit the vehicle and shelter under the overpass structure. This advice from pre-1994 guidance has been retracted; the 1994 Northridge earthquake collapsed several overpasses, and the confined space beneath an overpass offers no protection against a falling deck. If your vehicle is positioned under an overpass, drive forward or backward to clear the structure before stopping.

Near Buildings: Falling Debris Dangers

The hazard zone adjacent to multistory buildings during strong shaking is defined by the distance that facade materials can travel when dislodged. Unreinforced parapet walls — the low walls above rooflines common in pre-1940s commercial buildings — are notorious failure points that project debris outward at speed. 无筋砌体未配置钢筋加固的砖石或砌块结构，对地震震动极为脆弱。无筋砌体建筑是全球地震死亡人数中占比最高的建筑类型。 buildings can shed entire wall sections during shaking greater than intensity VII. The safe distance from a 10-story building is at minimum 30 feet; for older masonry construction, double this estimate.

Glass curtain walls on modern commercial buildings present a different profile: the glass itself is typically laminated safety glass that fractures into small pieces rather than large sheets, but the entire window unit including frame can fail as an assembly during severe racking of the building frame. Move perpendicular to the building face to exit the fall zone rather than running parallel to the facade where you remain exposed throughout the run.

After shaking stops, do not re-enter buildings until they have been assessed by structural engineers or building officials. Many earthquake casualties occur during re-entry to structurally compromised buildings, either because of continuing damage from 余震在同一断层区域内、发生于主震之后的较小地震。余震序列可持续数周至数年，最大余震的震级通常比主震低1.0至1.2级。 sequences or because of interior hazards not visible from the exterior. Wait for official clearance, particularly for older buildings or those showing visible cracking.

At the Beach: Tsunami Evacuation

If you feel strong, prolonged shaking while at or near the coast, treat it as a 海啸由水下地震导致海底突然位移而产生的一系列海浪。海啸可以喷气机般的速度（时速700公里以上）穿越整个大洋盆地。 warning and evacuate immediately to high ground — do not wait for an official warning. The largest tsunamis arrive within minutes of the generating earthquake in near-field scenarios, and the time to reach the 海啸疏散区标有前往高地疏散路线、存在海啸淹没风险的指定区域。沿海地区若感受到强烈震动，应立即开始疏散。 boundary may be less than fifteen minutes. Natural warning signs — the unusual retreat of water from the beach, a loud roaring sound from the ocean, or an unusual wave — indicate that the first tsunami wave is imminent.

Move inland and uphill as rapidly as possible. A minimum elevation of 100 feet above sea level provides protection from most tsunami scenarios, but large subduction-zone events such as a Cascadia Subduction Zone rupture can generate runup exceeding 100 feet in topographically focused areas. If you cannot reach high ground in time, the upper floors of a steel-reinforced concrete building may provide 原地避险在地震期间或震后留在当前位置而非疏散的做法。适用于建筑结构完好且不存在海啸风险的情况。 protection as a vertical evacuation refuge.

Never return to the beach after the first wave has passed. Tsunami 次生地震灾害由地震震动引发而非震动本身直接造成的灾害，包括海啸、滑坡、液化、火灾、水坝溃决及化学品泄漏等，其造成的损失往往超过震动本身。 include multiple waves over a period of several hours, with the first wave often smaller than subsequent arrivals. The sea will appear to recede again between waves, which triggers fatal re-entry by people who believe the event is over. Official all-clear announcements from the Pacific Tsunami Warning Center or equivalent authority are the only reliable signal that it is safe to return to coastal areas.

In the Mountains: Landslide Risk

Strong earthquake shaking destabilizes slopes by reducing the effective friction between soil and rock layers, triggering 地震诱发滑坡由地震震动引发的土壤和岩石沿坡向下的运动。滑坡可将整个社区掩埋，其造成的伤亡有时甚至超过震动本身。 events at distances far from the epicenter. The risk is highest on steep slopes with loose soils, slopes that have been recently burned in wildfires, and slopes already saturated by rainfall. When shaking begins in mountainous terrain, immediately assess your position relative to upslope terrain and move to flat ground or solid rock outcrops if possible.

A 地震诱发滑坡由地震震动引发的土壤和岩石沿坡向下的运动。滑坡可将整个社区掩埋，其造成的伤亡有时甚至超过震动本身。 triggered by earthquake shaking may begin during the shaking itself or in the minutes to hours following the mainshock as residual vibration propagates through saturated soils. If you hear cracking sounds in trees, see dust rising from slopes above you, or observe water and debris beginning to flow on previously dry slopes, move laterally across the slope rather than down the fall line. Lateral movement takes you out of the primary debris path; running downhill puts you ahead of fast-moving debris for only the seconds before the flow accelerates.

After shaking stops, do not assume that mountain roads are passable. Rock falls, road collapse, and bridge damage are common on mountain highways after significant earthquakes. Wait at a safe assembly point for official assessment of road conditions before attempting to drive out of mountainous terrain.

Bridges, Overpasses, and Tunnels

Bridge and overpass structures in the United States are designed to varying seismic standards depending on their construction date and jurisdiction. Pre-1971 structures in California and pre-1975 structures in most other western states were designed without modern seismic requirements and carry elevated collapse risk during strong shaking. If you are on a bridge or overpass when shaking begins, move to the nearest open roadway off the structure as quickly as safely possible.

If you are in a tunnel when shaking begins, pull over safely, stay in your vehicle, and protect yourself from falling materials. Modern mountain and highway tunnels are generally among the most seismically resilient structures because the surrounding rock constrains movement, but older cut-and-cover tunnels in urban areas can experience portal collapse and internal cracking. Do not exit your vehicle in an unlit, debris-strewn tunnel environment; wait for emergency response or official guidance before proceeding.

After a large earthquake, assume all bridges and overpasses should be inspected before use. Route around bridge structures if alternate surface roads are available. Use Distance from Epicenter to assess how close your location is to the estimated epicenter and calibrate your expectations for infrastructure damage accordingly.