2009 L'Aquila earthquake region saw dozens of significant aftershocks following the main earthquake. The strongest, which hit at 19:47 CEST on 7 April, measured magnitude 5.3 and caused further damage. According to the Italian National Geophysics Institute director Boschi, the aftershock epicentres migrated south-east, thus lessening the risk of further major shocks near populated areas. Aftershocks caused safety problems for rescue crews searching for injured victims trapped in precarious structures in the historic center of L'Aquila, a medieval city. Using cranes and backhoes to remove loose bricks and broken timbers, the crews were aware that even a small aftershock could have triggered the
Olancha Earthquake Sequence (2009) and the nearby Owens Valley are common" and that she expected that the ongoing Ridgecrest earthquake sequence would result in aftershocks in the high 4 magnitude range. Connections between earthquake-prone areas and their history of high magnitude shocks have contributed to the latter liquefaction present in the Olancha earthquake sequence in 2009 also assisting with scientific research. In 1872 an earthquake of magnitude 7.4 to 7.9 occurred in Lone Pine is located 37 kilometres north of Olancha. The 1872 Lone Pine earthquake also demonstrated horizontal ground deformation, eventuating to a 350,000 m graben which eventually was filled with water and