Tsunami is a Japanese word which means harbor wave and is used as the scientific term for seismic sea wave generated by an undersea earthquake or possibly an undersea landslide or volcanic eruption. When the ocean floor is tilted or offset during an earthquake, a set of waves is created similar to the concentric waves generated by an object dropped into the wave. Most tsunamis originate along the Ring of Fire, a zone of volcanoes and seismic activity, 32.500 km long that encircles the Pacific Ocean. Since 1819, about 40 tsunami have struck the Hawaiian Islands.

A tsunami can have wave lengths, or widths, of 100 to 200 km, and may travel hundreds of kilometres across the deep ocean, reaching speeds of about 725 to 800 kilometres an hour. Upon entering shallow coastal waters, the wave, which may have been only about half a metre high out at sea, suddenly grows rapidly. When the wave reaches the shore, it may be 15 metres high or more. Tsunamis have tremendous energy because of the great volume of water affected. They are capable of obliterating coastal settlements.

Tsunami should not be confused with storm surges, which are domes of water that rise underneath hurricanes or cyclones and cause extensive coastal flooding when the storms reach land. Storm surges are particularly devastating if they occur at high tide. A cyclone and accompanying storm surge killed an estimated 500,000 people in Bangladesh in 1970. The tsunami which truck south and southeast Asia in late 2004 killed over 200 thousand people.

What is the zone of volcanoes and seismic activity in the world called?

Câu hỏi liên quan

• The author mentions "several representative handfuls" in the passage in order to show ______.

• What do pads help the players to protect?

• The main idea of this passage is that .................

ZUNIA12

• The word ‘congested’ in paragraph 1 could best be replaced by ___.

• According to the passage, which of the following is NOT true?

• According to the passage, which of the following is NOT true about a logrolling?

• When is the wedding ceremony completed?

• According to paragraph 3, which of the following fields is NOT suitable for a person who does not want to live in a big city?

• According to the passage, to learn new information, low-achieving students do NOT .............

• Which of the followings is not mentioned as part of the “new media”?

• Pollution in water is noticed .............

• According to the passage, ..................

• The word "related" in paragraph 1 is closest in meaning to _______.

• In what part of the calculator are the processing and memory units? 

• Based on the passage, what is probably true about the south of France?

• The author claims all of the following to be the benefits of rooftop gardens except .............

• The author mentions the trail pheromone of the leafcutter ant in line 11 to point out ........

• The word “hidden” in paragraph 1 is closest in meaning to ______.

• What does the author mean by staring that, "At interpersonal levels, tone may reflect ideas and feelings over and above the words chosen" in lines 8- 9?

• The author believes that rote rotation is ........