最近因爲海地，智利，臺灣南部接連發生6.7到8.8級的地震（前幾天嘉義又有一次5級地震），於是一時之間“太平洋兩岸的地震高危險國家與地區都要小心，下一個發生地震的可能就是這裡“的説法流傳。我在網上瀏覽的時候，發現下面這個還滿有意思的文章：專家們根據各種資料，推論出三百年前在太平洋美國西北區曾發生了這麽一件事.....不知道，這個“1700年1月26日”的日期——還説是“晚上九點”——他們是怎麽訂出來的？我們就姑妄聽之吧

文章出處：http://www.historylink.org/index.cfm?DisplayPage=output.cfm&file_id=5098
Earthquake of enormous magnitude hits the Pacific Northwest coast on January 26, 1700.

HistoryLink.org Essay 5098

On January 26, 1700, at about 9:00 p.m. Pacific Standard Time a gigantic earthquake occurs 60 to 70 miles off the Pacific Northwest coast. The quake violently shakes the ground for three to five minutes and is felt along the coastal interior of the Pacific Northwest including all counties in present-day Western Washington. A tsunami forms, reaching about 33 feet high along the Washington coast, travels across the Pacific Ocean and hits the east coast of Japan. Japanese sources document this earthquake, which is the earliest documented historical event in Western Washington. Other evidence includes drowned groves of red cedars and Sitka spruces in the Pacific Northwest. Indian legends corroborate the cataclysmic occurrence.

The Earth Moves

The earthquake ruptured what is known as the Cascadia subduction zone -- the area of overlap between two of the tectonic plates that make up the earth's surface, the Juan de Fuca plate and the North American plate. The Cascadia subduction zone extends from Vancouver Island, British Columbia (about 49 degrees 30 minutes North Latitude) south to Cape Mendocino in northern California (about 40 degrees North Latitude). The earthquake dropped the entire Pacific Northwest ocean coastline three to six feet. The tsunami, up to 33 feet high, inundated the ocean coast.

This was one of the largest earthquakes the Pacific Northwest has ever had. It compares with two disastrous earthquakes: the March 27, 1964 Alaska earthquake, which measured 9.2 moment magnitude, and the May 21-22, 1960 Chile earthquake, which measured 9.5 moment magnitude.

Japan's Orphan Tsunami

The tsunami traveled across the Pacific Ocean for some 10 hours and at midnight on January 27, 1700, local time, it hit the east coast of Honshu Island, the main island of Japan. Four contemporary Japanese sources describe the 6- to 10-foot-high tsunami and five of the towns it inundated along 600 miles of the Honshu Island coast.

The Japanese call the tsunami their "orphan tsunami" because no earthquake felt in Japan accompanied it.

Seawater-drowned Groves and Indian Legends

Drowned groves of trees occur in several places in the Pacific Northwest. They have been dated within 30 or 40 years of the known date of the earthquake, which is suggestive but not conclusive. However, carbon dating of the tree rings of a seawater-drowned red cedar near the Copalis River in Grays Harbor County show that the tree died between August 1699 and May 1700, that is, in the same earthquake.

Native Americans witnessed this earth-shattering event. Ruth Ludwin, a University of Washington geophysics professor has searched for Indian legends that could refer to the event. She has found many similar tales of plains becoming oceans, mudslides, and the like.

The Hoh Indians of the Forks area of the Olympic Peninsula tell of an enormous "shaking, jumping and trembling of the earth ..." (The Seattle Times). The Makah who live on Neah Bay at the northwest tip of the continent have a version in which a whale is delivered to the mouth of a river and saves the people who had been starving. This legend forms the basis for the tribe's whale hunt.

Sources:
Kenji Satake, Kunihiko Shimazaki, and Yoshinobu Tsuji, “A Possible Cascadia Earthquake of January 26, 1700 as Inferred from Tsunami Records in Japan,” Program with Abstracts. Geological Association of Canada Annual Meeting May 17-19, 1995, Vol. 20 (1995), A-93; Kenji Satake, Kunihiko Shimazaki, Yoshinobu Tsuji, and Kazue Ueda, “Time and Size of a Giant Earthquake in Cascadia Inferred from Japanese Tsunami Records at January 1700,” Nature, Vol. 379 (January 18, 1996), 246-249; Hiroo Kanamori and Thomas H. Heaton, “The Wake of a Legendary earthquake,” Nature, Vol. 379 (January 18, 1996), 203-204; Kenji Satake and Yuichiro Tanioka, “Tsunami Heights along the Pacific Northwest Computed from M=9 Earthquake of January 1700,” 1996 Abstracts with Programs. The Geological Society of America 92nd Annual Cordilleran Section, Vol. 28, No. 5 (April 1996), 108; Elizabeth Murtaugh, "Legends Validate Quake Theory," The Seattle Times, July 14, 2002 (http://seattletimes.nwsource.com).

By Greg Lange , January 23, 2003
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Yahoo Bable Fish和我合作的譯文

1700年1月26日，極大的強烈大地震擊中Pacific Northwest coast
《HistoryLink.org雜文5098》

1700年1月26日，美國西岸時間晚上九點，離Pacific Northwest coast的外海60到70英里發生一次極強大地震。地震讓地面猛烈地搖動三到五分鐘，Pacific Northwest coast的沿海內陸，包括今日華盛頓州西部各縣，都感覺到此次地震。海嘯形成，華盛頓州沿岸海嘯到達大约33英尺高，並穿越太平洋擊中日本東部海岸。更有日本的資料文件證明這次地震，也提供華盛頓州西部關於此歷史事件最早的記載。其他證據包括在太平洋西北區被淹沒的red cedar(刺柏/檜木）和Sitka spruces（雲杉）樹叢。印第安傳說確認了此巨變的發生。

地（面移）動

地震爆裂了所謂Cascadia subduction zone，Cascadia 隱沒帶（消亡帶） -- 组成Juan de Fuca 板塊和北美洲板塊的地殼構造板塊之間重叠區域。 Cascadia隱沒帶從溫哥華，英屬哥倫比亞南邊(大约北緯49度30分)延伸至北加利福尼亞(大约北緯 40度)。 地震使整個太平洋西北海洋海岸線下降了三到六英尺。 海嘯， 高達33英尺，淹沒了海洋海岸。

這是Pacific Northwest coast最大的一次地震。 它可和 1964年3月27日阿拉斯加地震，9.2級，和1960年5月21-22智利地震，9.5級，二次大地震相比。

日本的孤兒海嘯

海嘯橫跨太平洋移動了10個小時左右，於1700年1月27日，當地时间的午夜擊中了本州東岸，日本的主要大島。 四個當代日本資料來源，描述了6 到10英尺高的海嘯，以及本州島沿岸600英里所被淹沒的五個城鎮。

日本稱此海嘯為「孤兒海嘯」，因為日本沒有地震能與之相比。

海水被淹沒的樹叢和印第安傳奇

在Pacific Northwest 的幾個地方發生樹叢被淹沒，時期可能在這個地震的30或40年内，此點僅可作爲參考但非結論。然而，在Grays Harbor County， Copalis 河附近，被海水淹沒的red cedar樹叢的年輪碳測年，顯示這樹是死於1699年8月和1700年5月之間，剛好就是這次地震。

美國原住民目擊了這個驚天動地的事件。Ruth Ludwin，華盛顿大學地球物理教授搜尋了可能與此事件有關的印第安傳奇。 她找到許多平原變為海洋，泥流的傳說，以及其他類似的故事。

Olympic Peninsula 的Fork 地區的Hoh 印地安人曾談到極大的「地球搖晃，跳動和打顫…」 ((The Seattle Times))。在洲大陸西北角的Neah Bay居住的Makah部落的一個故事版本是，有鯨魚送到河口並且救了飢餓的人民。 這個傳奇成為部落鯨魚狩獵的依據。
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中文維基百科相關註解：

Pacific Northwest coast，太平洋西北地區。其實是美國西北區。

subduction zone ，隱沒帶/消亡帶。隱沒帶存在於聚合板塊邊緣（convergent plate boundary）。海洋板塊擴張到大陸板塊邊緣，因為海洋板塊較重，會沉入大陸板塊之下，形成聚合板塊邊緣。

carbon dating，radiocarbon dating，放射性碳定年法，又稱碳測年。