The earthquake happened at 5:21 a.m. Alaskan time registered as a 4.9 and the USGS is saying it is an aftershock. Since this earthquake was much closer to the city of Anchorage it felt stronger.

For more info, please read the original article by KTUU:
https://www.ktuu.com/content/news/50-magnitude-earthquake-felt-near-Anchorage-on-Wednesday-USGS-shows-503554641.html