Lub Rift Valley nyob rau sab hnub tuaj Africa yog qhov txhaum loj heev hauv lub ntiaj teb. Dhau los ntawm Northern Ethiopia mus rau hauv nruab nrab ntawm Mozambique. Lub rift hav pib nyob rau hauv lub Ethiopian Highlands thiab stretches raws lub meridian rau ntau txhiab kilometers, muab faib ua ceg (tag nrho ntev yog ntau tshaj 9000 km). Qhov dav yog mus txog 200 mais, thiab qhov tob ntawm qhov txhaum loj no txawv ntawm ob peb puas meters mus rau ib mais.
Tshawb nrhiav keeb kwm
Lub Great African Rift Valley tau pom thawj zaug thaum xyoo pua 19th. Tam sim no nws tuaj yeem pom meej ntawm qhov chaw.
Nws tau txais nws lub npe los ntawm Askiv geologist John W alter Gregory, uas kawm East Africa thiab Australia. Fossilized seem ntawm hominids (ib tsev neeg ntawm cov primates siab tshaj plaws, suav nrog tib neeg) tau pom nyob rau hauv cov chaw no.
geology
Lub Rift Valley tau tsim nyob rau hauv Oligocene-Quaternary lub sij hawm vim muaj kev hloov pauv hauv lub ntiaj teb cov pob zeb nrog cov khaus heevvolcanic kev ua ub no vim qhov kev hloov ntawm cov lithospheric daim hlau (African thiab Arabian). Nws muaj ob ceg, sab hnub tuaj (Gregory's Rift) stretches sab qaum teb ntawm Lake Victoria thiab mus rau Hiav txwv Liab kev nyuaj siab.
Ntawm txoj kev nws hla Tanzania thiab Kenya. Qhov thib ob sab hnub poob ceg yog luv dua, Albertine Rift. Sab qaum teb ntawm qhov txhaum tau tig mus rau Hiav Txwv Liab, muaj dej, txhua xyoo kev nyuaj siab no maj mam txav mus los vim muaj kev tsim cov dej hiav txwv tsis tu ncua.
kev sib cav yog dab tsi?
Lub rift kwj ha zoo tshaj plaws hu ua East African rift system. Ib qho rift yog ib qho kev nyuaj siab loj heev nyob rau hauv lub ntiaj teb crust uas tshwm sim ntawm qhov chaw ntawm rupture ntawm lub ntiaj teb crust thaum nws raug rau tensile rog los yog longitudinal hloov chaw ntawm ob daim hlau. Xws li qhov tawg tuaj yeem tsim rau hauv av thiab hauv dej hiav txwv. Muaj cov cheeb tsam nyob rau hauv lub rift system uas dej hiav txwv crust tuaj yeem tsim. Ib qho piv txwv ntawm qhov tshwm sim hauv Great Rift Valley yog Afar Basin, nyob rau sab qaum teb.
Afar Valley
Qhov no yog qhov kev nyuaj siab tob tob uas tau poob mus rau 150 meters hauv qab dej hiav txwv raws li cov txheej txheem geological. Daim av no tseem hu ua "Afar Daim duab peb sab", txij li cov kev sib tshuam sib tshuam ntawm Gulf of Aden thiab Hiav Txwv Liab tau hais nrog cov kab ke ntawm cov teb chaws East African rifts. Kev nyem thiab kev nyab xeeb tau pab tsim ib qho chaw kub tshaj plaws hauv ntiaj teb. Qhov nruab nrab qhov ntsuas kub tsawg kawg yog + 25 degrees, thiab qhov siab tshaj plaws yog +35, dej nag txhua xyoo yog 200 millimeters. Afar kev nyuaj siab yog txog ob lab xyoo, nws tau tsim nyob rau hauv lub sijhawm Quaternary. Volcanoes nce raws Afar ciam teb, ib txhia ntawm lawv active.
Dabbahu Volcano muaj qhov siab ntawm 1442 meters, nws paub txog nws qhov tawg hauv xyoo 2005. Ua ntej lub roob hluav taws, av qeeg tau tshwm sim, uas tshwm sim los ntawm qhov tawg loj tsim nyob rau hauv lub ntiaj teb crust. Nws hu ua Dabbahu Fault. Cov kws tshawb fawb ntseeg tias qhov kev txhaum no ua ntej pib ntawm kev sib cais ntawm Somali phaj los ntawm African. Yog li ntawd, Africa yuav muab faib ua ob zaug yav tom ntej. Lub Afar Valley yog qhov thib ob, tom qab Ireland, qhov chaw koj tuaj yeem kawm cov dej hiav txwv dej ncaj qha rau thaj av.
Lwm qhov kev nyuaj siab tseem muaj npe nrov rau nws lub roob hluav taws - Erta Ape. Nws yog lub roob hluav taws hluav taws xob uas tau ua haujlwm tsis tu ncua txij li xyoo 1976 thiab tsuas yog ib qho ntawm lub ntiaj teb nrog ob lub pas dej lava.
Volcanoes ntawm Great Rift Valley
Nyob rau sab hnub tuaj ceg ntawm lub hav yog lub roob hluav taws siab tshaj plaws hauv Africa - Kilimanjaro, uas yog tib lub sijhawm qhov siab tshaj plaws ntawm thaj av loj. Nws yog qhov muaj peev xwm ua tau zoo, cov pa hluav taws xob tau pom thiab ntseeg tias lub khob hliav qab tuaj yeem tawg, ua rau muaj kev tawg loj heev. Ntawm lub ncov tseem ceeb ntawm Kilimanjaro, magma yog ze heev rau saum npoo.
Lub Ngorongoro volcanic caldera tau tshwm sim tom qab kev puas tsuaj ntawm lub roob hluav taws loj 2.5 lab xyoo dhau los. Txoj kab uas hla ntawm nws crater ranges ntawm 17 mus rau 21 kilometers. Nws qhov tob yog 610 meters, tag nrho cheeb tsam yog 265 square kilometers. ATMuaj ntau lub roob hluav taws hauv Great Rift Valley, qhov siab tshaj plaws yog Elgon, Kilimanjaro thiab Kenya. Txawm tias National Park mob siab rau volcanoes tau raug tsim; nws nyob rau sab qaum teb sab hnub poob ntawm Rwanda. Muaj volcanoes Sabinyo, Gahinga, Mukhabura, Bisoke, Karisimbi.
Great Lakes of Africa
Lub Rift Valley hla lub pas dej ntawm Africa, ntawm lawv muaj cov loj - Victoria, Nyasa, Tanganyika. Thiab cov dej me me.
Southwest of the Afar depression in the rift zone, tag nrho cov pas dej tau tsim: Abaya, Zvay, Shala, Chamo.
Lake Rudolph tau tsim nyob rau ntawm qhov chaw ntawm lub ntiaj teb crust trough ntawm Kenyan thiab Ethiopian arches. Ntawm no yog Rudolph ntawm tib lub npe nrog lub pas dej.
Tanganyika yog lub pas dej dej ntshiab tshaj plaws hauv ntiaj teb. Nws qhov ntev yog 700 km. Nws belongs rau sab hnub poob ceg ntawm lub rift hav, nrog rau cov pas dej - Albert, Kivu, Rukva, Eduard.
Lake Victoria yog lub pas dej loj tshaj plaws hauv teb chaws Africa thiab lub pas dej loj tshaj plaws thib ob tom qab Upper (hauv North America) ntawm lub ntiaj teb.
Nyasa. Hauv thaj tsam ntawm lub pas dej no, cov ceg ntoo sab hnub tuaj thiab sab hnub poob ntawm Great Rift Valley koom thiab mus rau Hiav Txwv Indian.
