More than 250,000 people in California, who live in coastal zones, are in danger due to flooding by a potential tsunami, according to research of the American Center of Geophysics (USGS).
According to the research, waves with eight meters height or more could affect northern California in an earthquake with magnitude 8 in the region.
The survey refers to the 2004 tsunami in the Indian Ocean and 2011 in Japan and highlights "The tragic consequences that were caused by the recent devastating tsunami, revealed their potential risk." "Historic and geological evidences show that the coast of California have already been hit by tsunami."
The Report that was drafted by the Disaster Management Agency of California includes detailed maps showing coastlines, which are most at risk, from San Diego to Los Angeles and Oakland, near San Francisco.
The total number of people living in areas that are likely to be flooded by tsunami is 267,000, while 169,000 others work in these areas. The number of people can be increased depending on the time of day, for example in tourist beaches.
The tsunamis which are formed far from the coastlines are less risky because the waves are smaller and the authorities have enough time to issue the warning.
But there is an even greater danger in case of an earthquake from Cascadia fault line that spans an area of about 1,000 km from northern California to Vancouver.
The fault is activated and has caused tsunami at least seven times during 3,500 years, with intervals ranging from 140 to 1,000 years ... The last dates back to 1700.
"A future earthquake that will be linked to the Cascadia fault line (over magnitude 8) will cause waves of eight meters or bigger and will flood these areas within 15 to 20 minutes from the initial shock," warns the report.
"Southern California is likely to be hit by a tsunami without the initial earthquake being felt and waves would get there at about an hour after the quake," the research results.