Map showing the distribution of aftershocks in the week following the magnitude-7.8 main event, as well as the rupture patches of historical earthquakes in the surrounding area. A magnitude-6.1 occurred The number of aftershocks increased daily, and a magnitude-6.1 occurred within days, and just west of, the main shock. Another magnitude-6.1 in the western Shumagin Islands took place the day after this figure was created. (See https://earthquake.alaska.edu/earthquakes for an up-to-date, interactive map of earthquakes in the region.) One question scientists will address is whether the aftershocks map out a continuous rupture across the Shumagin Gap. Credit: Alaska Earthquake Center