The 2024 Great Hawaii ShakeOut — USGS Volcano Watch

In Hawaii, earthquakes are a common occurrence, and we should always practice earthquake preparedness. Millions of people around the world practice “DROP, COVER, and HOLD ON” annually on the third Thursday of October.  That includes us in Hawaii! 

Back in my hanabata (younger) days, we would sometimes hear these melodic chimes slowly moving through the neighborhood. You couldn’t see where it was at first, but you knew what it was immediately. That sweet sound signaled that the manapua truck was coming by. As kids, we would hear that sound and run outside to look for the truck and wait in anticipation—all the while yelling to our neighbors that “the manapua man is coming!” in case they didn’t already know.

As an adult, I basically do the same thing nowadays at the USGS Hawaiian Volcano Observatory (HVO). Only the manapua trucks are volcanic eruptions (or intrusions if they fail to break the Earth’s surface), the sweet melodic chimes are earthquakes that get louder and more frequent as the magma gets closer to the surface.

Not all earthquakes in Hawaii are caused by magma movement, though; some of the most damaging earthquakes are caused by structural adjustments from the weight of our islands pushing down on the Pacific Plate.

A lot has changed since manapua trucks roamed through neighborhoods—particularly with how communication happens.

Back then, we had one phone number for the entire house. That number rang one phone (maybe two if you were lucky) that was either in the kitchen or hallway, plugged into the wall. For decades, this seemed to be the case.

Then, technological advancements unleashed a barrage of new possibilities. Computers became common fixture at schools and households and with them came the internet. Phones detached from walls, then shrank in size, then shrank some more, then they shrank some more! Actually, every bit of technology shrank—computers, the internet, phones—they all fit in one pocket now!

With all the advances in technology, including Machine Learning at its current state, we have yet to be able to predict earthquakes successfully. There is no notification that anyone can send out before a large earthquake occurs. All we can do is prepare for the shaking when—not if—a big one hits.

Although earthquakes cannot be predicted before they happen, technology is inching us closer to that fantasy by detecting, measuring, and locating intense ground shaking as quickly as it is happening.

The United States has two earthquake early warning (EEW) systems: ShakeAlert—a USGS-led collaboration between federal and state agencies, university researchers, and industry partners—sends notifications to folks in California (since 2019), Oregon, and Washington (since 2021); Google, an industry partner in the ShakeAlert EEW consortium, announced in September 2024 that they plan to roll out the Android Earthquake Alerts System (EAS) for the rest of the country—the 47 States and five U.S. Territories. It is important to note that Google’s EAS is (1) solely for Android devices and (2) proprietary, and (3) not tied to any government agency.

Regardless of which EEW you may encounter, they are most beneficial for people away from the epicenter, or where the earthquake originated. If ground shaking is expected to be intense, the notification will say, “DROP, COVER, and HOLD ON”, because the most likely causes of earthquake injuries are: (1) you fall down, and/or (2) things fall down on you.

Drop to the ground on your hands and knees as soon as you realize than an earthquake is happening.

Cover you head and neck with your arm if possible, or crawl under a sturdy table or next to a bed to shelter yourself from falling objects.

Hold on to your shelter until the shaking stops, as strong earthquakes may shift the cover away.

Because “lucky we live Hawaiʻi,” you might be near the ocean or near sea level when a strong earthquake occurs. In this case, head to higher ground after the intense shaking and look for notifications from the Pacific Tsunami Warning Center (PTWC).

We invite you to join us in the 2024 Great Hawaii ShakeOut next week, at 10:17 a.m. on October 17 (10/17). Start by registering online at ShakeOut.org/Hawaii beforehand, where you’ll receive valuable updates and resources on what to do before and after an earthquake.

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Volcano Watch is a weekly article and activity update written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates. Today's article is written by HVO seismologist Jefferson Chang.