Magnitude 2.8 earthquake — 31 km NNW of Covelo, CA

A small earthquake has given parts of northern California a bit of a shake, though it's unlikely to have caused any damage.

The tremor struck about 31 kilometres north-northwest of Covelo, a small town in Mendocino County, at just after half past eleven last night, British time. The US Geological Survey measured it at magnitude 2.8 — the sort of quake that feels like a lorry rumbling past if you're near the epicentre, but which most people sleep right through.

What happened

The quake occurred at a depth of just under seven kilometres, which is relatively shallow. Shallow quakes tend to be felt more strongly at the surface than deeper ones, though at this magnitude we're still talking about a gentle rattle rather than anything alarming.

Covelo itself sits in the Round Valley, a remote and rather beautiful part of California where the coast ranges meet dense forest. It's not heavily populated — the sort of place where you're more likely to be woken by wildlife than by seismic activity.

The USGS data is still being refined, as is normal with these events, but the initial readings give a clear enough picture. No reports of damage or injuries have emerged, which is entirely expected for a quake of this size.

Nothing to worry about

For those unfamiliar with earthquake scales, a magnitude 2.8 sits well below the threshold where structural damage occurs. You'd need to be sitting still and paying attention to notice it at all, and even then you might wonder if you'd imagined it. Magnitude 2 to 3 quakes happen thousands of times a day around the world — it's just that most occur in places where nobody lives, or deep enough that nobody notices.

California, of course, sits on several active fault lines, and small tremors like this are part of the normal geological conversation the earth has with itself. They're reminders that we live on a planet that's very much alive, but at this scale they're about as threatening as a cat stretching.

If you've got family or friends in that corner of California, they've almost certainly slept through the whole thing. And if they did feel it, they've probably already forgotten about it by breakfast time.

Were you anywhere near Covelo when this happened? Did you feel anything, or do you remember a quake that gave you a proper fright? We'd love to hear from you in the comments below.