Vertical and horizontal evacuation are strategies for providing safety to humans in case of tsunami, hurricane or other natural disaster. [1]
Vertical and horizontal evacuation are strategies for providing safety to humans in case of tsunami, hurricane or other natural disaster. [1]
In areas where horizontal evacuation to higher ground is impossible, vertical evacuation to higher areas of a structure may be a way to shelter individuals from the surge of water, several meters high, that can follow an earthquake in coastal areas. [2] [3]
The U.S. Federal Emergency Management Agency published design guidelines for vertical evacuation structures in 2008. [4] According to the American Society of Mechanical Engineers, serious discussions about vertical evacuation began in the United States following the 2011 Tōhoku earthquake and tsunami. [5] The American Society of Civil Engineers adopted an updated edition of its building standards in September 2016, including tsunami hazards for the first time. [6]
The first vertical evacuation site in the United States was Ocosta Elementary School, constructed in 2015–2016 on the Pacific Ocean coast in Westport, Washington, where a Cascadia subduction zone magnitude 9+ earthquake is expected to cause great tsunamis. [7] [8]
An alternative to vertical evacuation is horizontal evacuation, for instance a hurricane evacuation route. Critics of vertical evacuation planning have charged it with justifying even greater human density in areas prone to disaster, and prefer low density growth with horizontal evacuation planning. [9]
Earthquake preparedness is a set of measures taken at the individual, organisational and societal level to minimise the effects of an earthquake. Preparedness measures can range from securing heavy objects, structural modifications and storing supplies, to having insurance, an emergency kit, and evacuation plans.
The 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26, 1700, with an estimated moment magnitude of 8.7–9.2. The megathrust earthquake involved the Juan de Fuca Plate from mid-Vancouver Island, south along the Pacific Northwest coast as far as northern California. The length of the fault rupture was about 1,000 kilometers, with an average slip of 20 meters (66 ft).
The Cascadia subduction zone is a convergent plate boundary that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American Plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.
Megathrust earthquakes occur at convergent plate boundaries, where one tectonic plate is forced underneath another. The earthquakes are caused by slip along the thrust fault that forms the contact between the two plates. These interplate earthquakes are the planet's most powerful, with moment magnitudes (Mw) that can exceed 9.0. Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust earthquakes.
Emergency management is the organization and management of the resources and responsibilities for dealing with all humanitarian aspects of emergencies. The aim is to prevent and reduce the harmful effects of all hazards, including disasters.
Paleoseismology looks at geologic sediments and rocks, for signs of ancient earthquakes. It is used to supplement seismic monitoring, for the calculation of seismic hazard. Paleoseismology is usually restricted to geologic regimes that have undergone continuous sediment creation for the last few thousand years, such as swamps, lakes, river beds and shorelines.
The seismicity of the Sanriku coast identifies and describes the seismic activity of an area of Japan. Seismicity refers to the frequency, type and size of earthquakes experienced over a period of time. The Sanriku coast is a descriptive term referring to the coastal areas of the former provinces of Rikuō in Aomori, Rikuchū in Aomori, and Rikuzen in Miyagi.
Hazus is a geographic information system-based natural hazard analysis tool developed and freely distributed by the Federal Emergency Management Agency (FEMA).
The Huu-ay-aht First Nations (HFN) is a First Nations band government based on Pachena Bay about 300 km (190 mi) northwest of Victoria on the west coast of Vancouver Island in British Columbia, Canada. The traditional territories of the HFN make up the watershed of the Sarita River. The HFN is a member of the Nuu-chah-nulth Tribal Council and is a member of the Maa-nulth Treaty Society. It has recently completed and ratified its community constitution and has successfully ratified the Maa-nulth Treaty on 28 July 2007. The Legislative Assembly of British Columbia passed the Maa-nulth First Nations Final Agreement Act on Wednesday, 21 November 2007 and celebrated with the member-nations of the Maa-nulth Treaty Society that evening.
A submarine, undersea, or underwater earthquake is an earthquake that occurs underwater at the bottom of a body of water, especially an ocean. They are the leading cause of tsunamis. The magnitude can be measured scientifically by the use of the moment magnitude scale and the intensity can be assigned using the Mercalli intensity scale.
A teletsunami is a tsunami that originates from a distant source, defined as more than 1,000 km (620 mi) away or three hours' travel from the area of interest, sometimes travelling across an ocean. All teletsunamis have been generated by major earthquakes such as the 1755 Lisbon earthquake, 1960 Valdivia earthquake, 1964 Alaska earthquake, 2004 Indian Ocean earthquake, and 2021 South Sandwich Islands earthquakes.
The 1992 Cape Mendocino earthquakes occurred along the Lost Coast of Northern California on April 25 and 26. The three largest events were the M7.2 thrust mainshock that struck near the unincorporated community of Petrolia midday on April 25 and two primary strike-slip aftershocks measuring 6.5 and 6.6 that followed early the next morning. The sequence encompassed both interplate and intraplate activity that was associated with the Mendocino Triple Junction, a complex system of three major faults that converge near Cape Mendocino. The total number of aftershocks that followed the events exceeded 2,000.
The National Tsunami Warning Center (NTWC) forms part of an international tsunami warning system (TWS). It serves as the operations center for all coastal regions of Canada and the United States, except Hawaii, the Caribbean, and the Gulf of Mexico. Headquartered in Palmer, Alaska, it is operated by the National Oceanic and Atmospheric Administration (NOAA).
The 1932 Jalisco earthquakes began on June 3 at 10:36 UTC with a megathrust event that registered 8.1 on the moment magnitude scale. With a maximum perceived intensity of X (Extreme) on the Mercalli intensity scale, at least 400 deaths were caused in Mexico and neighboring Guatemala. It was the first of a series of seismic events that affected parts of western Mexico during the month of June 1932, all reaching magnitude 7 or greater.
Due to the common occurrence of hurricanes in the coastal state of North Carolina, hurricane recovery in North Carolina is a large component of the state's emergency management efforts. Recovery from these tremendous storms at the local and state level is a large part of the aftermath of a hurricane. Gavin Smith and Victor Flatt stated that "Disaster recovery remains the least understood aspect of hazards management, when assessed relative to preparedness, response, and hazard mitigation." Smith and Flatt also went on to state that the role of the states is even less understood. The review of the plans and policies that instruct recovery, agencies involved, funding processes and budgets, and the environmental effects of a hurricane creates a better understanding of how North Carolina recovers from a hurricane.
Coastal hazards are physical phenomena that expose a coastal area to risk of property damage, loss of life and environmental degradation. Rapid-onset hazards last over periods of minutes to several days and examples include major cyclones accompanied by high winds, waves and surges or tsunamis created by submarine earthquakes and landslides. Slow-onset hazards develop incrementally over longer time periods and examples include erosion and gradual inundation.
Ocosta Elementary School is a public elementary school in Westport, Washington, operated by the Ocosta School District.
Ghost forests are areas of dead trees in former forests, typically in coastal regions where rising sea levels or tectonic shifts have altered the height of a land mass. Forests located near the coast or estuaries may also be at risk of dying through saltwater poisoning, if invading seawater reduces the amount of freshwater that deciduous trees receive for sustenance.
Pachena Bay is located 13 km (8.1 mi) south of Bamfield in Pacific Rim National Park at the southern end of Vancouver Island, British Columbia, Canada. It was the location of a First Nation's village that was destroyed by a tsunami in 1700.
The 2021 Kermadec Islands earthquakes were a series of earthquakes with magnitudes of 8.1 and 7.4 that occurred at 19:28:31 UTC on 4 March 2021. The epicentres were located southeast of Raoul Island in the Kermadec Islands, part of the New Zealand outlying islands. The main magnitude 8.1 earthquake was preceded by a magnitude 7.4 foreshock and followed by a magnitude 6.1 aftershock. A separate, unrelated magnitude 7.3 earthquake occurred off the coast of the North Island of New Zealand, approximately 900 km to the south, several hours before the main quakes. As of January 2022, there have been thousands of aftershocks, with more than a dozen of them exceeding magnitude 6.
The term vertical evacuation refers to a social process where agents relocate from one threatened area to an upper area or areas of the same physical structure.