Volcano Watch: The 2024 Great Hawai‘i ShakeOut

“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 Hawaiian Volcano Observatory seismologist Jefferson Chang.

In Hawai‘i, 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, including us in Hawai‘i.

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 at the U.S. Geological Survey Hawaiian Volcano Observatory, only the manapua trucks are volcanic eruptions — or intrusions, if they fail to break the Earth’s surface.

The “sweet melodic chimes” I now hear slowly moving through the ground are earthquakes that get louder and more frequent as magma gets closer to the surface.

Not all earthquakes in Hawai‘i 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, too, 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.

This was the norm for decades.

Technological advancements then unleashed a barrage of new possibilities.

Computers became common fixtures at schools and households. 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 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, 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 systems:

• ShakeAlert, a U.S. Geological Survey-led collaboration between federal and state agencies, university researchers and industry partners, has sent notifications to folks in California since 2019 and Oregon and Washington state since 2021.
• Google, an industry partner in the ShakeAlert earthquake early warning systems consortium, announced in September 2024 that it plans to roll out the Android Earthquake Alerts System for the other 47 states and five U.S. territories. It is important to note, however, that Google’s system is solely for Android devices, proprietary and not tied to any government agency.

Regardless of which earthquake early warning system you might 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 falling down and/or things falling down on you:

• Drop to the ground on your hands and knees as soon as you realize an earthquake is happening.
• Cover your head and neck with your arms, 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 might 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.

We invite you to join us at 10:17 a.m. Oct. 17 for the 2024 Great Hawai‘i ShakeOut.

Start by registering online, where you’ll receive valuable updates and resources about what to do before and after an earthquake.

Volcano Activity Updates

Kīlauea is not erupting. Its USGS Volcano Alert level is at Advisory.

Unrest continues at a low level in the middle East Rift Zone following the Sept. 15-20 eruption.

During the past week, about 40 earthquakes were located in Kīlauea summit region, and about 100 were located in the upper-to-middle East Rift Zone. Ground deformation rates have greatly decreased since the eruption, but data show magma is continuing to move at a low rate from the summit to the middle East Rift Zone.

Future intrusive episodes and eruptions could occur with continued magma supply.

The most recent measurement of sulfur dioxide emission rate at the summit was 60 tonnes per day Sept. 17, and emissions were not detected at or downwind of the eruption site as of Sept. 23.

Mauna Loa is not erupting. Its USGS Volcano Alert Level is at Normal.

No earthquakes were reported felt in the Hawaiian Islands during the past week.

The Hawaiian Volcano Observatory continues to closely monitor Kīlauea and Mauna Loa.

Visit the observatory’s website for past “Volcano Watch” articles, Kīlauea and Mauna Loa updates, volcano photos, maps, recent earthquake information and more. Email questions to askHVO@usgs.gov.