The Mira Vista Country Club in El Cerrito: the epicenter of Monday morning's earthquake according to USGS

Update, 3:20 pm: USGS updated the initial earthquake quake that happened at 5:33:12 am this morning from magnitude 2.9 to 3.5.

Update, 9:35 am: This morning’s 4.0 magnitude earthquake, which was 5.7 miles deep, was immediately preceded by a 2.9 magnitude quake — which is why many reported feeling two distinct shakes. It was followed by two aftershocks: a 2.0 magnitude quake at 6:03am, then a 1.1 magnitude at 6:29am.

Berkeleysiders who lived very close by felt rattled. Reader Sharris wrote: “It felt very strong here in Richmond’s Marina Bay neighborhood. I haven’t felt anything so strong since the 1989 quake. The house was a-shaking and it was very noisy. It seemed like the roof would fall in any moment. Glad that’s over!”

Update: 5:40am: USGS downgraded the magnitude to 4.0.

What felt like two strong earthquakes struck at 5:33am Monday morning. USGS put the epicenter as one mile north of El Cerrito, four miles NNW of Berkeley.

The magnitude at the time of writing was determined as 4:3.

Tracey Taylor is co-founder of Berkeleyside and co-founder and editorial director of Cityside, the nonprofit parent to Berkeleyside and The Oaklandside. Before launching Berkeleyside, Tracey wrote for...