C\u00e1c nh\u00e0 khoa h\u1ecdc \u0111\u00e3 ph\u00e1t hi\u1ec7n b\u1eb1ng ch\u1ee9ng v\u1ec1 m\u1ed9t tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t kh\u1ed5ng l\u1ed3 \u2014 ho\u1eb7c hai tr\u1eadn li\u00ean ti\u1ebfp \u2014 \u0111\u00e3 \u0111\u00e1nh v\u00e0o khu v\u1ef1c Puget Sound \u1edf T\u00e2y B\u1eafc Th\u00e1i B\u00ecnh D\u01b0\u01a1ng c\u00e1ch \u0111\u00e2y g\u1ea7n 1.100 n\u0103m. Nghi\u00ean c\u1ee9u, \u0111\u01b0\u1ee3c c\u00f4ng b\u1ed1 tr\u00ean t\u1ea1p ch\u00ed Science Advances, \u0111\u00e3 s\u1eed d\u1ee5ng ph\u01b0\u01a1ng ph\u00e1p x\u00e1c \u0111\u1ecbnh tu\u1ed5i c\u00e2y qua v\u00f2ng n\u0103m \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh r\u1eb1ng hai v\u00f9ng \u0111\u1ee9t g\u00e3y g\u1ea7n Seattle \u0111\u00e3 ph\u00e1t sinh trong kho\u1ea3ng th\u1eddi gian s\u00e1u th\u00e1ng gi\u1eefa n\u0103m 923 v\u00e0 924 SCN.<\/p>\n\n
Ph\u00e1t hi\u1ec7n n\u00e0y th\u00e1ch th\u1ee9c c\u00e1c nghi\u00ean c\u1ee9u tr\u01b0\u1edbc \u0111\u00e2y cho r\u1eb1ng khu v\u1ef1c n\u00e0y ch\u1ec9 nh\u1ea1y c\u1ea3m v\u1edbi nh\u1eefng tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t nh\u1ecf h\u01a1n. Nh\u1eefng k\u1ebft qu\u1ea3 m\u1edbi cho th\u1ea5y khu v\u1ef1c bao g\u1ed3m Seattle, Tacoma v\u00e0 Olympia, bang Washington, c\u00f3 th\u1ec3 tr\u1ea3i qua c\u00e1c tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t m\u1ea1nh h\u01a1n so v\u1edbi nh\u1eefng g\u00ec \u0111\u00e3 \u0111\u01b0\u1ee3c d\u1ef1 \u0111o\u00e1n tr\u01b0\u1edbc \u0111\u00e2y.<\/p>\n\n
C\u00e1c tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t li\u00ean quan \u0111\u1ebfn nhi\u1ec1u \u0111\u1ee9t g\u00e3y c\u00f9ng m\u1ed9t l\u00fac th\u01b0\u1eddng l\u00e0 lo\u1ea1i g\u00e2y thi\u1ec7t h\u1ea1i n\u1eb7ng nh\u1ea5t m\u00e0 m\u1ed9t khu v\u1ef1c c\u00f3 th\u1ec3 g\u1eb7p ph\u1ea3i. Tuy nhi\u00ean, ch\u00fang hi\u1ebfm g\u1eb7p v\u00e0 kh\u00f3 quan s\u00e1t trong h\u1ed3 s\u01a1 l\u1ecbch s\u1eed. Tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 trong nghi\u00ean c\u1ee9u m\u1edbi c\u00f3 kh\u1ea3 n\u0103ng l\u00e0 k\u1ebft qu\u1ea3 c\u1ee7a m\u1ed9t s\u1ef1 g\u00e3y \u0111\u1ee9t \u0111a \u0111\u1ee9t g\u00e3y, khi\u1ebfn n\u00f3 tr\u1edf n\u00ean \u0111\u1eb7c bi\u1ec7t nguy hi\u1ec3m.<\/p>\n\n
\u0110\u1ec3 x\u00e1c \u0111\u1ecbnh th\u1eddi gian c\u1ee7a tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t c\u1ed5, c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u \u0111\u00e3 ph\u00e2n t\u00edch c\u00e1c v\u00f2ng c\u00e2y th\u00f4ng Douglas Fir t\u1eeb s\u00e1u \u0111\u1ecba \u0111i\u1ec3m quanh Puget Sound. B\u1eb1ng c\u00e1ch so s\u00e1nh c\u00e1c v\u00f2ng c\u00e2y v\u1edbi nhau v\u00e0 v\u1edbi m\u1ed9t chu\u1ed7i tham chi\u1ebfu, h\u1ecd x\u00e1c \u0111\u1ecbnh r\u1eb1ng c\u00e1c c\u00e2y \u0111\u00e3 ch\u1ebft trong kho\u1ea3ng th\u1eddi gian t\u1eeb th\u00e1ng 10 n\u0103m 923 \u0111\u1ebfn th\u00e1ng 3 n\u0103m 924. \u0110i\u1ec1u n\u00e0y cho ph\u00e9p h\u1ecd \u0111\u1ecbnh v\u1ecb tr\u1eadn (c\u00e1c) \u0111\u1ed9ng \u0111\u1ea5t v\u00e0o kho\u1ea3ng s\u00e1u th\u00e1ng \u0111\u00f3.<\/p>\n\n
\u0110\u1ec3 t\u0103ng c\u01b0\u1eddng ni\u1ec1m tin v\u00e0o k\u1ebft qu\u1ea3, nh\u00f3m nghi\u00ean c\u1ee9u \u0111\u00e3 t\u00ecm ki\u1ebfm trong c\u00e1c v\u00f2ng c\u00e2y m\u1ed9t d\u1ea5u hi\u1ec7u \u0111\u1eb7c tr\u01b0ng gi\u00fap \u0111\u1ecbnh tu\u1ed5i: m\u1ed9t \u0111\u1ed9t bi\u1ebfn b\u1ee9c x\u1ea1 sao g\u1ecdi l\u00e0 s\u1ef1 ki\u1ec7n Miyake. S\u1ef1 ki\u1ec7n n\u00e0y, c\u00f3 th\u1ec3 l\u00e0 m\u1ed9t c\u01a1n b\u00f9ng ph\u00e1t n\u0103ng l\u01b0\u1ee3ng m\u1eb7t tr\u1eddi ho\u1eb7c m\u1ed9t ng\u00f4i sao n\u1ed5, s\u1ebd \u0111\u1ec3 l\u1ea1i m\u1ed9t d\u1ea5u hi\u1ec7u t\u0103ng \u0111\u1ed9t bi\u1ebfn n\u1ed3ng \u0111\u1ed9 carbon\u201114 trong c\u00e2y. H\u1ecd \u0111\u00e3 ph\u00e1t hi\u1ec7n m\u1ed9t s\u1ef1 ki\u1ec7n nh\u01b0 v\u1eady v\u00e0o kho\u1ea3ng n\u0103m 774\u2011775 SCN v\u00e0 d\u00f9ng n\u00f3 l\u00e0m \u0111i\u1ec3m tham chi\u1ebfu trong vi\u1ec7c \u0111\u1ecbnh tu\u1ed5i, x\u00e1c nh\u1eadn v\u00f2ng c\u00e2y cu\u1ed1i c\u00f9ng \u0111\u01b0\u1ee3c l\u1ea5y m\u1eabu l\u00e0 n\u0103m 923 SCN.<\/p>\n\n
D\u1ef1a tr\u00ean k\u1ebft qu\u1ea3, c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u \u01b0\u1edbc t\u00ednh r\u1eb1ng trong kho\u1ea3ng th\u1eddi gian s\u00e1u th\u00e1ng, c\u00f3 th\u1ec3 l\u00e0 hai tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t g\u1ea7n nhau v\u1edbi c\u01b0\u1eddng \u0111\u1ed9 7,5 v\u00e0 7,3 ho\u1eb7c m\u1ed9t tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t \u0111a \u0111\u1ee9t g\u00e3y duy nh\u1ea5t kho\u1ea3ng c\u01b0\u1eddng \u0111\u1ed9 7,8 \u0111\u00e3 \u0111\u00e1nh v\u00e0o khu v\u1ef1c. K\u1ecbch b\u1ea3n m\u1ed9t tr\u1eadn duy nh\u1ea5t c\u00f3 kh\u1ea3 n\u0103ng x\u1ea3y ra kho\u1ea3ng ba l\u1ea7n so v\u1edbi hai tr\u1eadn ri\u00eang bi\u1ec7t.<\/p>\n\n
M\u1ed9t tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t c\u01b0\u1eddng \u0111\u1ed9 7,8 nh\u01b0 m\u00f4 t\u1ea3 trong b\u00e0i b\u00e1o m\u1edbi s\u1ebd gi\u1ea3i ph\u00f3ng n\u0103ng l\u01b0\u1ee3ng g\u1ea5p 38 l\u1ea7n so v\u1edbi m\u1ed9t tr\u1eadn c\u01b0\u1eddng \u0111\u1ed9 6,7, m\u1ee9c m\u00e0 c\u00e1c m\u00f4 h\u00ecnh r\u1ee7i ro tr\u01b0\u1edbc \u0111\u00e2y d\u1ef1a v\u00e0o. \u0110i\u1ec1u n\u00e0y c\u00f3 kh\u1ea3 n\u0103ng g\u00e2y ra s\u00f3ng th\u1ea7n \u0111\u1ecba ph\u01b0\u01a1ng c\u00f9ng v\u1edbi thi\u1ec7t h\u1ea1i lan r\u1ed9ng v\u00e0 th\u01b0\u01a1ng vong.<\/p>\n\n
K\u1ebft qu\u1ea3 nghi\u00ean c\u1ee9u nh\u1ea5n m\u1ea1nh nhu c\u1ea7u c\u1eadp nh\u1eadt c\u00e1c m\u00f4 h\u00ecnh r\u1ee7i ro \u0111\u1ec3 t\u00ednh \u0111\u1ebfn kh\u1ea3 n\u0103ng x\u1ea3y ra c\u00e1c tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 nh\u01b0 v\u1eady. C\u00e1c m\u00f4 h\u00ecnh hi\u1ec7n t\u1ea1i kh\u00f4ng t\u00ednh \u0111\u1ebfn nh\u1eefng tr\u1eadn m\u1ea1nh nh\u01b0 v\u1eady, d\u1eabn \u0111\u1ebfn vi\u1ec7c \u0111\u00e1nh gi\u00e1 r\u1ee7i ro th\u1ea5p h\u01a1n th\u1ef1c t\u1ebf v\u00e0 thi\u1ebfu chu\u1ea9n b\u1ecb \u0111\u1ed1i ph\u00f3 th\u1ea3m h\u1ecda.<\/p>\n\n
M\u1eb7c d\u00f9 kh\u1ea3 n\u0103ng m\u1ed9t s\u1ef1 ki\u1ec7n c\u1ef1c \u0111oan x\u1ea3y ra trong m\u1ed9t n\u0103m nh\u1ea5t \u0111\u1ecbnh l\u00e0 th\u1ea5p, nghi\u00ean c\u1ee9u n\u00e0y l\u00e0m n\u1ed5i b\u1eadt t\u1ea7m quan tr\u1ecdng c\u1ee7a vi\u1ec7c chu\u1ea9n b\u1ecb cho c\u00e1c tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t th\u1ea3m h\u1ecda. C\u00e1c quy chu\u1ea9n x\u00e2y d\u1ef1ng v\u00e0 k\u1ebf ho\u1ea1ch ph\u1ea3n h\u1ed3i kh\u1ea9n c\u1ea5p n\u00ean \u0111\u01b0\u1ee3c xem x\u00e9t v\u00e0 c\u1eadp nh\u1eadt \u0111\u1ec3 ph\u1ea3n \u00e1nh ti\u1ec1m n\u0103ng c\u1ee7a c\u00e1c tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t l\u1edbn h\u01a1n so v\u1edbi d\u1ef1 \u0111o\u00e1n tr\u01b0\u1edbc \u0111\u00e2y.<\/p>\n\n
Tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 trong nghi\u00ean c\u1ee9u m\u1edbi c\u00f3 kh\u1ea3 n\u0103ng l\u00e0 tr\u1eadn m\u1ea1nh nh\u1ea5t trong v\u00f2ng 16.000 n\u0103m qua \u1edf khu v\u1ef1c n\u00e0y. \u0110i\u1ec1u n\u00e0y nh\u1ea5n m\u1ea1nh t\u1ea7m quan tr\u1ecdng c\u1ee7a vi\u1ec7c nghi\u00ean c\u1ee9u v\u00e0 gi\u00e1m s\u00e1t li\u00ean t\u1ee5c \u0111\u1ec3 hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 c\u00e1c r\u1ee7i ro \u0111\u1ed9ng \u0111\u1ea5t \u0111ang \u0111e d\u1ecda T\u00e2y B\u1eafc Th\u00e1i B\u00ecnh D\u01b0\u01a1ng v\u00e0 ph\u00e1t tri\u1ec3n c\u00e1c chi\u1ebfn l\u01b0\u1ee3c gi\u1ea3m thi\u1ec3u hi\u1ec7u qu\u1ea3.<\/p>","protected":false},"excerpt":{"rendered":"
\u0110\u1ed9ng \u0111\u1ea5t Hai \u0110\u1ee9t G\u00e3y L\u1edbn C\u00f3 Th\u1ec3 \u0110\u00e3 \u0110\u00e1nh \u0110\u1ed9ng V\u00f9ng T\u00e2y B\u1eafc Th\u00e1i B\u00ecnh D\u01b0\u01a1ng C\u00e1ch \u0110\u00f3 1.100 N\u0103m Nghi\u00ean C\u1ee9u M\u1edbi Ti\u1ebft L\u1ed9 C\u01b0\u1eddng \u0110\u1ed9 \u0110\u1ed9ng \u0110\u1ea5t…<\/p>\n","protected":false},"author":2,"featured_media":25392,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[728],"tags":[4866,19690,19691,1643,613,8053,6748],"class_list":["post-14684","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth-sciences","tag-earthquakes","tag-fault-zones","tag-hazard-mitigation","tag-ancient-history","tag-scientific-discovery","tag-pacific-northwest","tag-tree-rings"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/posts\/14684","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/comments?post=14684"}],"version-history":[{"count":2,"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/posts\/14684\/revisions"}],"predecessor-version":[{"id":25393,"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/posts\/14684\/revisions\/25393"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/media\/25392"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/media?parent=14684"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/categories?post=14684"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/vi\/wp-json\/wp\/v2\/tags?post=14684"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}