—" Well," you " know " …" a " main " earthquake " is " always " preceded " by " a " series " of " smaller " tremors " for " energy," but " they " get " more " and " more " frequent " as " the " time " of " the " main-shock " gets " closer.—" Ok," so " what?"…—" So," that ' s " what " we ' re " detecting " now." Increasingly " frequent " shocks," of " low " value," a " few " people " are " aware " of," but " that " seismographs " record " very " well." But " the " tremors " are " increasing " more " frequent," with " a " magnitude " that " at " times " gets " up," even " if " slightly," sometimes " gets " down.
—" Well," but " is " this " enough " to " suspect " a " major " earthquake?" Small " tremors " in " the " earth ' s " crust " are " common," I " think "…"—" Captain " Jim " added.
—" Yes," it " is " so " …" But " besides " that," in " the " Philippines " Sea " we " have " recorded " a " similar " situation," that " is " shocks " of " low " energy " but " increasingly " frequent," even " in " the " southZeast " of " China," in " the " mainland,"…" I " mean "…" similar " situations," in " two " places " not " very " far " from " each " other," are " deBinitely " related.—" Wow!—" You " see," Jim," if " we " analyse " what " happened " in " the " last " few " years," it " seems " that " the " Earth " has " awakened " from " a " deep " sleep," and " today " it " is " shaken " by " tremors " bouncing " from " place " to " place " on " the " planet." So " that," an " earthquake " in " an " area " may," in " some " cases," increase " the " risk " that " another " earthquake " occurs " in " an " adjacent " zone," but " also " in " a " distant " area." Once " we " geologists " didn’ t " think " this " could " happen," we " said " that " every " earthquake " was " an " event " in " itself," that " could " not " possibly " affect " other " areas " of " the " planet," but " today " we " have " changed " our " minds." In " fact," some " faults " may " start " moving " if " they " are " also " affected " by " pressures " of " low " value " and " can " involve " other " planar " fractures " at " short " or " long " distance.—" Is " it " true?" Really?—" Let ' s " scroll " the " latest " events " …"—" Chiao " Chuang " went " on " saying."—" In " September " 2009," an " earthquake " of " magnitude " 8.1 " shook " the " Samoa " Islands " in " the " PaciBic " Ocean," causing " dozens " of " victims " and " generating " a " massive " tsunami " that " crossed " the " entire " ocean." Sixteen " hours " later," another " violent " earthquake " of " magnitude " 7.6 " struck " the " south " of " Sumatra," causing " hundreds " of " deaths.—" Yes," that ' s " true "…—" What " is " the " distance " between " the " two " places?" Nearly " ten " thousand " kilometres " …" But " before " Samoa," if " you " remember," between " Sumatra " and " the " Andaman " Islands " another " terrible " earthquake " occurred " in " December " 2004," magnitude " 9 " on " the " Richter " scale "…—" Yes," I " remember " that " incident." At " that " time " I " was " in " Malaysia.—" Well," they " hadn’ t " recorded " an " earthquake " of " magnitude " 8.5 " or " greater " for " forty " years." That " earthquake " off " Sumatra " occurred " at " a " depth " of " 30 " km " below " the " sea " level " and " generated " a " tsunami " that " developed " a " series " of " waves," which " struck " large " coastal " areas " of " Asia …" There " were " six " waves " in " total," they " occurred " until " ten "