* Astronomy

Blobrana · L

RE: Tsunami Facts

Blobrana · L

Coastal towns such as Folkestone and Dover could be at risk from a tsunami, according to a Timewatch programme to be shown tonight.
The show, on BBC2 at 8pm, examined previous undersea tremors in UK history and discovered they have occurred on many occasions.

Read more

Blobrana · L

Tsunamis

Click to Play | View Details

Blobrana · L

NOAA deployed the final two tsunami detection buoys in the South Pacific this week, completing the buoy network and bolstering the U.S. tsunami warning system. This vast network of 39 stations provides coastal communities in the Pacific, Atlantic, Caribbean and the Gulf of Mexico with faster and more accurate tsunami warnings.
These final two deep-ocean assessment and reporting of tsunami (DART) stations, deployed off the Solomon Islands, will give NOAA forecasters real-time data about tsunamis that could potentially impact the U.S. Pacific coast, Hawaii and U.S. Pacific territories. Tsunami sensors are now positioned between Hawaii and every seismic zone that could generate a tsunami that would impact the state and beyond, including the U.S. West Coast. Buoys already in the western Atlantic, Gulf of Mexico and Caribbean have been keeping watch over the U.S East and Gulf coasts.

Read more

Blobrana · L

Evidence of past events and modelling of potential future events suggest that tsunamis are significant threats to Oregon coastal communities. Although a potential tsunami-inundation zone from a Cascadia Subduction Zone earthquake has been delineated, what is in this area and how communities have chosen to develop within it have not been documented. A vulnerability assessment using geographic-information-system tools was conducted to describe tsunami-prone landscapes on the Oregon coast and to document city variations in developed land, human populations, economic assets, and critical facilities relative to the tsunami-inundation zone. Results indicate that the Oregon tsunami-inundation zone contains approximately 22,201 residents (four percent of the total population in the seven coastal counties), 14,857 employees (six percent of the total labour force), and 53,714 day-use visitors on average every day to coastal Oregon State Parks within the tsunami-inundation zone. The tsunami-inundation zone also contains 1,829 businesses that generate approximately $1.9 billion in annual sales volume (seven and five percent of study-area totals, respectively) and tax parcels with a combined total value of $8.2 billion (12 percent of the study-area total). Although occupancy values are not known for each facility, the tsunami-inundation zone also contains numerous dependent-population facilities (for example, adult-residential-care facilities, child-day-care facilities, and schools), public venues (for example, religious organizations and libraries), and critical facilities (for example, police stations). Racial diversity of residents in the tsunami-inundation zone is low, with 96 percent identifying themselves as White, either alone or in combination with one or more race. Twenty-two percent of the residents in the tsunami-inundation zone are over 65 years in age, 36 percent of the residents live on unincorporated county lands, and 37 percent of the households are renter occupied. The employee population in the tsunami-inundation zone is largely in accommodation and food services, retail trade, manufacturing, and arts and entertainment sectors.
Results indicate that vulnerability, described here by exposure (the amount of assets in tsunami-prone areas) and sensitivity (the relative percentage of assets in tsunami-prone areas) varies considerably among 26 incorporated cities in Oregon. City exposure and sensitivity to tsunami hazards is highest in the northern portion of the coast. The City of Seaside in Clatsop County has the highest exposure, the highest sensitivity, and the highest combined relative exposure and sensitivity to tsunamis. Results also indicate that the amount of city assets in tsunami-prone areas is weakly related to the amount of a community's land in this zone; the percentage of a city's assets, however, is strongly related to the percentage of its land that is in the tsunami-prone areas. This report will further the dialogue on societal risk to tsunami hazards in Oregon and help identify future preparedness, mitigation, response, and recovery planning needs within coastal cities and economic sectors of the state of Oregon

Source USGS

Download 43-page Report (2.3mb, PDF)
Download the supporting database (184kb, xls)

Blobrana · L

Tsunami Early Warning

Blobrana · L

RE: Tsunami Facts

Blobrana · L

In the wake of yesterdays tsunami in the Solomon Islands, National Geographic News looks at how the killer waves are caused, what the warning signs are, and how to respond when a tsunami threatens.

A tsunami is a series of great sea waves caused by an underwater earthquake, landslide, or volcanic eruption. More rarely, a tsunami can be generated by a giant meteor impact with the ocean.

Scientists have found traces of an asteroid-collision event that they say would have created a giant tsunami that swept around the Earth several times, inundating everything except the tallest mountains 3.5 billion years ago. The coastline of the continents was changed drastically and almost all life on land was exterminated.

Read more