Segments of many faults are observed to slip aseismically at the surface. On the central segment of the San Andreas Fault, aseismic slip accumulates largely in creep events: few mm bursts of slip which occur every few weeks to months. But even though we have observed creep events worldwide since the 1960s, we still do not know how big most events are or which forces drive them. To address this uncertainty, we systematically identify creep events along the central San Andreas Fault and determine their along‐strike rupture extents. We first use cross‐correlation and visual inspection to identify events at individual creepmeters. With data from 18 USGS creepmeters, we identify 2120 records of creep events between 1985 and 2020. We then search for slip that is closely timed across multiple creepmeters. We identify 306 instances of closely timed slip, which could indicate 306 creep events that rupture multiple creepmeter locations. Through visual inspection and statistical analysis of timing, we identify a variety of creep event types, including single‐creepmeter events, small (<2 km) events, medium‐sized (3–6 km) events, large (>10 km) events, and events that rupture multiple fault strands. The existence of many large (> $ > $few‐km) events suggests that creep events are not produced by small, rainfall‐associated perturbations; they are more likely driven by complex or heterogeneous frictional weakening and they may provide a window into the dynamics of a larger scale slip on the San Andreas Fault.

&lt;p&gt;The San Andreas fault has been observed to creep at the surface along the 175km section between San Juan Bautista and Cholame (Titus et al., 2011). This section is known as the creeping section and accumulates slip in two modes: during continuous background slip at a long term slip rate and in accelerated slip bursts known as creep events (Gladwin et al., 1994). But the size and importance of creep events remain unclear. Some researchers treat them as small, ~100-m-wide near-surface events (Gladwin et al., 1994), but others suggest that many creep events reach 4 km depth, connecting the surface to the seismogenic zone (Bilham et al., 2016). So, in this study, we systematically characterize the along-strike rupture extents of creep events along the San Andreas Fault, to determine if these are small, localized phenomena or large, segment-rupturing events.&lt;/p&gt;&lt;p&gt;We detect creep events and analyse their propagation using 18 USGS creepmeter records from the San Andreas Fault. Each creepmeter operated for at least 9 of the years between 1985 and 2020. To begin we systematically detect creep events using a cross-correlation approach. We identify periods that have significant slip and signals with high similarity to a template creep event. This automated detection allows us to produce a catalogue with 2000 creep events. The method detects at least 95% of the creep events identified by visual inspection.&lt;/p&gt;&lt;p&gt;Once we have found creep events at each creepmeter, we examine how creep events propagate. We compare creep event detections between pairs of creepmeters to determine how many creep events propagate from one creepmeter to the other. At the northern end of the creeping section, we observe that 18-28% of the creep events found at Harris Ranch are also found at Cienega Winery within 24hrs. This coincident timing implies that 18-28% of creep events in the north have an along-strike length of at least 4 km. Many creep events at the southern end of the creeping section appear to be even larger. For instance, a few events appear to be at least 31 km long; 10-38% of creep events at Slacks Canyon also observed at Work Ranch (31 km away) within 24hrs. These large along-strike rupture extents imply that creep events connect the slip and stress field over large regions of the San Andreas Fault. These events may play an important role in the slip dynamics of the creeping section.&lt;/p&gt;

&lt;p&gt;The San Andreas Fault has been observed to creep at the surface along the creeping section between San Juan Bautista and Cholame. Slip along this creeping section accumulates at a slow background rate that is punctuated by creep events: few-mm bursts of slip that occur every few weeks to months. Despite observations of these events dating back to the 1960s, we still do not know the rupture extent of these events or the forces that drive them, as previous estimations are confined to short observation periods or one location. So in this study, we systematically characterize creep events in terms of their along-strike rupture extent and determine the depth at which these events occur.&lt;/p&gt;&lt;p&gt;We detect and analyze creep event rupture extent using 18 USGS creepmeters and PBO strainmeters along the San Andreas fault. Using a cross-correlation approach, we systematically detect 2120 creep events in the creepmeter record spanning 1985 - 2020. Comparing the start times of these events, we identify 306 potential multi-creepmeter events and determine their potential along-strike rupture extent. Through both visual inspection and statistical analysis, we identify five creep event types, including single-creepmeter events, small (&lt;2 km) events, medium-sized (3-6 km) events, large (&gt;10 km) events and events that rupture multiple fault strands. We also repeated this analysis after removing events that may be driven by rainfall, and we find that only the correlation of the very largest creep events diminishes. This suggests that these kilometer-long events are not small rainfall-associated perturbations; they are likely to be driven by complex or heterogeneous frictional weakening at depth.&lt;/p&gt;&lt;p&gt;We are exploring more of the properties of creep events to understand better the driving physics, primarily depth, duration, slip and slip evolution. By determining these properties, we may be able to better discriminate between the driving models of creep events and provide a window into the dynamics of larger-scale slip on the San Andreas Fault.&lt;/p&gt;

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