2022年托福复习资料模拟试题及答案（四）

2022年托福复习资料模拟试题及答案（四）Some 800 years ago, Alaska”s Hubbard Glacier advanced toward the sea, retreated

2022年托福复习资料模拟试题及答案（四） Some800yearsago,Alaska”sHubbardGlacieradvancedtowardthe sea,retreated,andadvancedagain500yearslater.Since1895,this seventy-mile-longriveroficehasbeenflowingsteadilytowardtheGulf ofAlaskaatarateofapproximately200feetperyear.InJune1986, however,theglaciersurgedaheadasmuchas47feetaday. Meanwhile,awesterntributary,calledValerieGlacier,advancedupto 112feetaday.Hubbard”ssurgeclosedoffRussellFiordwitha formidableicedam,some2,500feetwideandupto800feethigh, whosecagedwatersthreatenedthetownofYakutattothesouth. About20similarglaciersaroundtheGulfofAlaskaareheading towardthesea.Ifenoughsurgeglaciersreachtheoceanandraisesea levels,westAntarcticiceshelvescouldriseofftheseafloorandbecome adrift.AfloodoficewouldthensurgeintotheSouthernSea.Withthe continuedriseinsealevel,moreicewouldplungeintotheocean, causingsealevelstoriseevenhigher,whichinturnwouldrelease moreiceandsetinmotionaviciouscycle.Theadditionalseaice floatingtowardthetropicswouldincreaseEarth”salbedoandlower globaltemperatures,perhapsenoughtoinitiateanewiceage.This