other faults, a large extent of the Hayward Fault trace is formed from a narrow complex zone of deformation which can span hundreds of feet in width. The transform boundary defined by the San Andreas Fault is not perfectly straight, and the stresses between the Pacific and North American Plates are diffused over a wide region of the West, extending as far as the eastern side of the Sierra Nevada Mountains. The Hayward Fault is one of the secondary faults in this diffuse zone, along with the Calaveras Fault to the east and the San Gregorio Fault, west of the San Andreas. The complete fault zone, including the Rodgers Creek fault, is divided by seismologists into three segments – Rodgers Creek, Northern Hayward, and Southern Hayward. It is expected that these segments may fail singly or in adjacent pairs, creating earthquakes of varying magnitude. The Association of Bay Area Governments (ABAG) in concert with other government agencies has sponsored the analysis of local conditions and the preparation of maps indicative of the destructive potential of these earthquakes. The various ABAG maps shown below represent some of the more likely possible combinations. While there are indications that a substantial earthquake on a nearby parallel fault can release stress and so also decrease the near-term probability of an earthquake, the opposite appears to be true concerning sequential segments. A release on a major segment can substantially increase the likelihood of an earthquake on an adjacent fault segment, increasing the likelihood of two major regional earthquakes within a period of a few months. Rodgers Creek Fault Zone The connection between the Rodgers Creek Fault Zone and the Hayward Fault Zone was unclear until 2015 when a survey of the floor of San Pablo Bay found that the ends of the two faults were smoothly linked between Point Pinole and Lower Tubbs Island. An alternate prior hypothesis suggested that the Hayward Fault and Rodgers Creek Fault were probably connected by a series of en echelon fault strands beneath San Pablo Bay. The new finding means that the Rodgers-Hayward system together could produce a quake with a magnitude as high as 7.2. It is also considered possible that a major seismic event on either fault may involve movement on the other, either concurrently or within an interval of up to several months. The Association of Bay Area Governments has prepared ground shaking maps that include