NGHliN Clhl - TRAO B 6 |
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r i i dsCt da t r a i qua n h u n g t h i e n t a i k h u n g k h i e p nhut dpng dat, s o n g t h a n . . . , t h a m chi c 6 n CO n g u y c o doi m a t v o i m p t t h a m hpa k h a c c h u a biet liic nao se x a y ra: Hien t u p n g d a o cue cua t u t r u o n g trai dat.Trong khu vye rdng 7,8 trieu km^
gdm mdt phan Idn Nam My, eac ve tinh ludn ludn bj de doa, ke dich da dugc xac dinh la hang van tan hat proton va electron do mat trdi phat xa ra vdi van tdc 800km/s. Binh thudng thi eae hat ay va dap vao tir trudng eiia hanh tinh chung ta d do eao hon 60.000km trong khdng gian, tao thanh mgt la chan va lam lech hudng cae tia vu tru. Trai dat dugc bao ve, trir trudng hgp bat thudng d Nam Dai Tay Duong*'', tai dd la chan bj sii> yeu ehi edn vai ba tram km be
day. Cae ve tinh vien thdng quy dao thap di qua khu vyc ay d do eao khoang 2.000km se bi tryc tiep ban pha trong nhieu phut bdi cac tia vu tru tir mat trdi. Cac hat proton di chuyen eae nguyen tir trong mang tinh the, pha huy nhat la eac bdng ban dan ciia cae eon bg dien tiir, hoac gay ra cae qua tai tai hai ve dien. Den kinh thien van Hubble eung phai ngat mgt sd dung eu de ty bao ve.
Viec nghien ciru cdc do gom cd dd giup phdt hien ra sir gidm sut ddng io nggi cua cudng dp dia tir trudng
Chiing ta chua biet ngudn gde cua sy bat thudng d Nam Dai Tay Duong, nhung hinh nhu nd gan lien vdi mdt hi?n tugng khac edn dang lo ngai hon: Tir nhieu the ky, cudng dg tir trudng toan bd eua trai dat giam xudng lien
between reversals during a reversal
Sd 12/2011 Thdng tin KH-CN Nghe An [34]
NGHIEN Cl/U - TRAO D 6 |
tue. Day la mgt dir kien suy ra tir nghien ciru cac dd gdm co. Cac dd vat bang dat set nung ed ehua nhirng tinh th6 chat khoang magnetit la mdt oxit sat ty nhien, bj nhiem tir nhieu hay it tiiy theo cudng dg dja tir trudng. Mgt khi magnetit bi nung cimg dat set thi cac tinh the dugc dn djnh. Dem nung mgt mau do gom thi tir tinh cae tinh the dugc giai phdng ra va cho ph^p do duge cudng dg chinh xac eua tir trudng vao thdi ki do gdm ay dugc che tao. Nhu vay, da ed the udc lugng rang cudng dg dja tir trudng giam di deu d^n tir hon
1.500 nam nay.
Dja tir ddo cue se k/tong gdy ra sa- dist vong /ldng loat cdc lodi, nhung thiet bi cdng nghe se bj dnh hudng
Ket qua do d^c do cac nha tham hiem va cac tiiuy thu tien hanh tren toan dja eau da x^c nh^n: Cudng dp tir trudng da giam 10% trong 150 nam. Jeremy Bioxam, nha Dja vat ly trudng D^i hge Harvard thu nhan: "That ki la, ngudn cua tic trudng nam tgi trung tdm qud ddt. Nd duac sinh ra bdi khdi nhdn rdn phia trong duac bao boc bdng khdi nhdn ldng ben ngodi gdm sat vd ken ndng chdy d 4.000"C. Hai khdi nhdn ndy quay khdng cung mdt tdc do vd phdt ra nhihig ddng dien gdy ra cdc tie trudng lan ra tren mat trdi ddt" Jeremy Bioxam giai thich: "Neu cd the dot ngdt cho ngimg hoat ddng cdi mdy phdt dien ndy, thi tic tnrdng phdi mdt 15.000 ndm de triet tieu" The nhung vdi van toe hien nay, nd se bien mat sau 1.500 nam, 6ky \k dieu bat binh thudng. Vay, d day cd van de khac. Larry Nervitt thude Phdng nghien ciru dja chat d Canada neu y kiSn: trong khi cyc dia ly eiia trai dat ludn ed djnh theo tryc quay eua trai dat, thi cue tir Bae eir di ehuySn hon
1.000km mdi the ky vdi van toe ngay cang tang. Nam 1970, eye tir Bae xe djch lOkm/nam, cdn bay gid thi tang Ien thanh 40km/nam.
d t/ti ky XVIII, dd xdy ra su bdt binh thudng nhu t/te
Tuy nhien, tir trudng khdng chi suy sut di ma thdi, cd nhirng vimg ma
hudng Bac Nam cua nd khdng dugc bao dam. 6 the ky XVIll, da cd sy bat binh thudng nhu vay d mien Nam chau Phi. Trong cae the ky, nd djeh \k phia Tay roi hgp vdi cai ma ngay nay ggi la sy bat thudng ciia Nam Dai Tay Duong. Day khdng ehi la mgt noi suy yeu don thuSn eiia tir trudng ma cdn la mgt khu vyc ma tai dd tir trudng bj I?eh hudng. V^y, dieu gi dang xay ra dudi chan ehung ta? Cau giai dap den tir phdng thi nghifm cua G.Gary Glatzmaier tai trudng Dai hge Santa Cruz (California My) chuyen vk ngi tir trudng eac tinh tu. Nam 1995, dng da lap ra mgt md hinh tin hgc de md phdng hoat dgng dja tir eua khoi nhan trai dat. Sau nhieu tuan ll tinh toan, ket qua th^t dang kinh ngac, tir trudng cua hanh tinh ehiing ta ed the bj dao nguge. Do nhieu hien tugng phiire t^p, eac eye ed thi ty ddi chd: eye Nam thanh eye Bac va nguge lai. Hien tugng bat thudng cua tir trudng cang tang, eye Bac di dgng va sy suy ygu qua nhanh eiia tir trudng ehi la cae bude dau eua mdt cudc dao Ign hoan vi eae eye.
Tuy nhien, hien tugng nay xuat hien khdng phai la Ian dau tien. Cac ddng nham thach tich tu tir nhieu trieu nam ehinh la nhirng kho luu trir dich thye ciia tir trudng'^' Cac tinh the hinh kim Ii ti eiia khoang magnetit tac ddng nhu nhirng kim la ban nhd va sap hang tren tir trudng, ghi cudng do va djnh hudng cua nd trong nham thach da ngudi lanh. Nhu the, cae nha khao ed tir hgc da xac djnh duge rang tir trudng trai dat da bj dao ngugc 300 lan trong 200 trieu nam lai day. Hg da nhan thay tir trudng suy yeu manh trude khi dao nguge. Day eung la thdi chiing ta dang sdng hien nay. Cae hoan vi nay xay ra trung binh eir 100.000 hoac 200.000 nam mdt Ian. Lan gan nhat cd ten la "Cudc dao eye Brunhes Mataya" da tir 780.000 nam, cudc tiep theo se den rat mudn, day la nhan xet cua Peter Olson, nha Dja vat li trudng Dai hgc Johns Hopkins. Vay vin de khdng phai la can biet cd xay ra mdt Ian nira hay khdng ma bao gid nd se xay ra. Sau ngan nam nira, cd the mugn, cd the nhanh hon, tii' trudng se bien mat hoan toan trong it nhat 1.000 nam vdi nhung hau qua nghiem trgng trudc khi phuc hdi dan.
Tat ed ede /odi vgt di tru se bi mdt p it uang /tudng Chua phai vi the ma da den ngay tan th6, bdi khi quyen edn bao ve ehiing ta khdi eae tae ddng doe hai eiia eac buc xa. Td tien ehung ta - ngudi Homo erectus da duge ma ehung ta tdn tai ngay nay la mdt minh chirng.
Nhung tat ea eude song tren trai dat se bj tac ddng. D^u tien la eae dgng vat ed kha nang thu nhan tir, nghTa la ed the tri giac tir trudng. Cac loai di trii: riia, chim chdc, ea voi, ea map... se bj anh hudng nang nhat. Tuy rdt hiem nguy eho eae loai, nhung khdng gay ra mdt eude diet vong quy md. Cae nha khoa hge ehua bao gid phat hien 6ugc mdi lien he nao giira hien tugng dao cyc tir vdi sy
So 12/2011 Thong tin KH-CN Nghe An (35]
tieu di?t hang lo^t cae loai sinh v§t.
Nhung doi vdi nen van minh cdng nghi?p cua chiing ta thi khdng phai nhu v^y. Kha lau trude hi?n tugng dao cyc, eae tran bao tir sg pha hdng mgi v? tinh eua ehung ta va ion hod khi quyen. The la het thdi cua h? v? tinh djnh vj tokn
Chu thich
NGHIEN CIJU - TRAO o 6 l
eau (GPS), di?n tho^i di dgng tokn eau... Vi vay, tot nhat la can chuan bj ddn trudc sy ki?n nay!
To chirc vu try chau Au nam 2012 s6 tung ra cugc khao sat Swarm. Ba v? tinh cua nd dugc trang bj cac thiet ke sieu nh^y s6 cung cap mgt ban do ehinh xac \k sy tien hoa eua tir quyen nham myc dich biet dugc chinh xac thdi diem eua sy dao Ign ckc cyc tir trudng trai dat./.
^'^ Tren qui dgo a dp cao 1.000m, kinh thien vdn vd tru Carol do thdng luang proton tic mat trdi. KT thugt ndy xdc djnh dugc cdc vimg xung quanh cua hi?n lugng bdt thudng ndy: Trong khu vwc Nam Dgi Tdy Dirang, cdc proton di qua dugc bdi tgi ddy tie trudng yeu nhdt tren hdnh linh. Ddi vdi cdc nhd khoa hgc, ddy la mgt bdng chdng cho thdy dia tir sdp bj ddo circ.
^ ^ C \ic lap nham thgch ke tiep nhau cua nui Ida Kilauea (Hawai) dugc cdu tgo rdi rdm nhu Id dirang xi (millefeuilles). Cdc nhd Dia vdt li dd cdn cic vdo dd de lim ra dugc bang chung ciia nhieu cugc ddo c\rc qua nhieu thien nien ki vd khdng dinh bao ldu nira se xdy ra cugc ddo cue cua tir tnrdng trdi ddt.
LV H m ^ "CtfC PH^l TRf^A/"...
(Tiep theo trang 25) Chua cd edng bd tdng ketehinh thue viec thyc hien de an va cae bai hgc kinh nghiem, nhung eac tieu chi kinh te xa hgi da dugc thdng ke eua 63 tinh thanh ca nudc nam 2010 cho thay rang, Nghe An van edn nhieu eon sd can tran trd, suy ngam so vdi eae tinh khae, dac biet Nghe An van la mgt tinh ngheo ciia ca nudc.
Ly thuygt "Cyc phat trien"
la mgt khai niem hiru ieh eho phan tieh khdng gian, la ly thuyet phye vy tryc tiep cho viec lua chgn lanh thd trgng
Tai lieu tham khao
diem. Vdi mgt lanh thd rgng Idn gan 14 ngan km (tuong duong vdi 9 tinh trung binh), trong khi kinh te mien Ddng chua du sue manh de kich cau kinh te mien Tay phat trien, do vay xay dyng "eye phat trien mien Tay" la mgt chiln luge hgp ly, thiet thye. "Cyc phat trien" la mgt khdng gian lanh thd ed kha nang hgi ty nhieu lgi the de tao nen sy dgt bien nham kich eau sy phat triln toan viing. Day la mgt van de khdng don gian, ddi hdi tinh Ngh? An can xay dyng mgt td
chirc ed nang lye (ed the mdi cac chuyen gia nudc ngoai va trong nude tham gia), xac djnh eho duge "circ phdt trien mien Tdy" \k viing nao va cd mgt co che du manh de dau tu cho lanh thd do trong khoang 5-7 nam, sau dd la thdi ky kich eau, Ian tda cua cue phat trien dd eho toan mien. Neu van de nay thyc hien duge thi se gdp phan rut ngan thdi gian phat trien kinh te mien Tay. Mien Tay can cd it nhat mgt "eye phat trien" de tao nen tinh dot pha eho sy phat trien./.
1. UBND tinh Ngh? An. Di dnphdt trien kinh le - xd hoi miin Tdy tinh Ngh? An din nam 2010.
2. UBND tinh Ngh? An. Ky yiu HQI thdo khoa hpc: Nhirng gidi pfidp thifc hi?n eo hi?u qud di dn phdi triin kinh ti - xa hpi mien Tdy Ngh? An. Thing 6/2008.
3. Vi?n Chi6n lixgrc phit triSn - Ban viing lanh th6. MQI sd ly luQn vi chenh l?ch vitng va gidi phdp han chi chenh lech vitng a Vi?t Nam. De tii nghien ciru khoa hpc cap B0, nim 1998.
4. UBND huy?n Quy Hgrp. Bdo cdo cong tdc qudn ly Nhd nuac vi hoai dpng khai thdc, ehi biin khodng sdn tren dfa bdn huy?n Quy Hpp ndm 2008.
5. CMC Thong ke Ngh? An. Nien gidm thdng ki ndm 2010.
6. T6ng cyc Th6ng ke Vi?t Nam. Nien gidm thdng ke ndm 2010.
7. So Ke hoach vS Diu tu Ngh? An. Bdo cdo di dn phdt triin tdng thi kinh li - xa hpi Ngh? An din ndm 2020. Nam 2007.
8. Bda Tiin phong. Cic so 311, 312 thing 11 /2009.
9. Ho Thj Thanh Van. Nghien ciru thuc trfing chenh l?eh vi mpt s6 vdn di kinh te - xa hpi tinh Ngh? An. D6 tii nghiSn ciiru khoa hpc cip Bp, nam 2007.