When was the last major earthquake in Hawaii?

When Was the Last Big One? Hawaii’s Earthquakes, Explained

Hawaii, beautiful as it is, owes its existence to volcanoes. And where there are volcanoes, there are bound to be earthquakes. We get little tremors pretty often, but what about the really big ones? The kind that can actually cause some serious trouble? Knowing when the last major earthquake rattled the islands helps us stay prepared and understand the risks.

What Do We Mean by “Major,” Anyway?

Okay, so what exactly counts as “major” when we’re talking about earthquakes? Well, scientists use something called the moment magnitude scale – it’s like the Richter scale’s cooler, more accurate cousin. Generally, anything around a magnitude 6.0 can start causing problems, especially in populated areas. Bump that up to a 7.0 or higher, and you’re talking about potentially major damage. Each point on that scale isn’t just a little bigger, either. It means about ten times the shaking and over thirty times the energy released!

Flashback: The 1868 Whopper

Let’s go way back. The biggest earthquake Hawaii ever recorded happened way back on April 2, 1868. Can you imagine? It was a magnitude 7.9 – absolutely massive. It caused a crazy tsunami and landslides. Sadly, it took 77 lives. The epicenter was down on the Big Island, near Pahala. That earthquake? It’s the one we measure all others against when we think about what’s possible here.

More Recent Shakers

Thankfully, we haven’t seen anything quite that big since. But we’ve definitely had some significant quakes since then. I remember hearing about the one on November 29, 1975. It was a 7.4, hit the eastern side of the Big Island, and sent a 47-foot tsunami crashing ashore! Then, more recently, in October 2006, a 6.7 rattled Kiholo Bay. That one caused damage all over the islands. I remember pictures falling off the walls – it was a wake-up call.

The 2018 Rumble

Now, the most recent earthquake that I’d call “major” happened on May 4, 2018. It was a 6.9 – not as big as the 1868 monster, but still plenty strong. It struck the eastern side of the Big Island again, near Leilani Estates, and was tied to all the volcanic activity going on at the time. It even caused a small tsunami. Luckily, nobody died, but it did cause some damage and made a lot of people evacuate.

The Bottom Line

So, if we’re talking magnitude 6.5 or higher, the last “major” earthquake in Hawaii was the 6.9 on May 4, 2018. But let’s not forget that the granddaddy of them all was the 7.9 back in 1868. Here’s the thing: Hawaii has thousands of earthquakes every year. Since 1868, we’ve had over 30 that were magnitude 6.0 or higher. It’s just part of living in paradise, I guess. But it’s a good reminder to be prepared, just in case the next “big one” decides to pay us a visit.