Buuxi weedha soo socota: Dhacdadii 1971 waxay ahayd tii ugu horaysay taxane ah (1987 Whittier Narrows, 1991 Sierra Madre,
1994 Northridge) ee dhulgariirrada waxyeelada leh ee ka dhacay cilladaha ka soo horjeeda ee aagga Los Angeles. Dhacdooyinka ayaa kiciyay doodo ku saabsan dhulgariirkii ugu weynaa ee laga yaabo inuu soo saaro mid ka mid ah cilladaha, gaar ahaan Transverse Ranges, laakiin barta diiradda lagu saarayo qiimeynta khatarta dhulgariirka ee California badanaa waa San Andreas Fault iyo cilladaha kale ee la xiriira. In kasta oo xogta paleoseismic-ka ee ku saabsan qalloocyada ka soo horjeeda ee aagga Los Angeles ay yar tahay, qodista qodista ee goob ku taal Sierra Madre-Cucamonga Fault ayaa shaaca ka qaaday in laba dhulgariir oo waaweyn oo taariikhi ah ay dhaceen 15,000 sano ee la soo dhaafay.