Kammala jumla mai zuwa: Saboda tarihinta na samar da manyan girgizar ƙasa (1857, 1906) cibiyar nazarin haɗarin girgizar ƙasa a California ita ce San Andreas System of Faults. Koyaya, tsarin kuskure, gami da Sierra Madre<unk>Cucamonga Fault System wanda ke gudana a kan iyakar San Gabriel da San Fernando Valleys, ya kuma haifar da jerin matsakaici zuwa manyan abubuwan da suka faru a Greater Los Angeles Area. Yankin yammacin wannan tsarin lalacewa ya fashe a cikin
1971 kuma an gano shi a matsayin daya daga cikin manyan manyan laifuka guda shida waɗanda ke haifar da barazana ga yankin da ke da yawan jama'a.