Did you feel that one?

[TomK]

Thanks. I got the warning a few seconds before the ground shook, so it really didn't help much, but I'm not sure what else the technology can do. It wasn't set up, so assume a recent update turned it on. I had no idea I would get a warning, but it happened. This was on a Samsung Android phone.

I suspect it will be very useful for folks on the US West Coast, where the warning might come several seconds to a minute before the ground starts moving. I'm glad it's implemented here; it's just that it's a small island, so I don't think you'll have time to do anything when you get the warning other than pick up the phone.

[ChunksterK]

I got a warning on my Android phone, but never having heard it before, I didn't know what it was until the shaking started a second or two later. I'm left wondering if distance from the epicenter has any effect on the amount of time between the alarm and felt motion.

[MyManao]

I'm left wondering if distance from the epicenter has any effect on the amount of time between the alarm and felt motion.

In Waipio Valley one often hears earthquakes coming as they shake the foliage, the trees and such, on the pali as they go. So you learn a certain sound means an earthquake is traveling through the valley, and can hear it long before it arrives. Usually the sound can be heard coming from the back of the valley, the direction most earthquakes come from, a second or two before they arrive in the front. It's an analog early warning system. The USGS now does the same digitally, which helps those with automated systems that would be better being offline when struck.

[sistersue]

The tectonic plate referenced is the slab of rock that makes up most of the ground the Pacific Ocean sits above. The rock, the crust of the earth. So, that crust, the Pacific Ocean Plate, is bearing a considerable amount of weight already. All that water weighs a bunch as it is.

The islands are made up of rock, which is heavier than the water. As such the weight of the islands causes the crust to deform, to bend downward into the underlying interior of the planet. Overall that weight creates a trough the islands sit in that is about 1 kilometer deeper than the general depth of the ocean’s seafloor.

It took a minute for that to sink into my brain!  Thank you, MyManao.

[TomK]

I got a warning on my Android phone, but never having heard it before, I didn't know what it was until the shaking started a second or two later.  I'm left wondering if distance from the epicenter has any effect on the amount of time between the alarm and felt motion.

Chunkster - the warnings are generated automatically by detecting "P" waves from the earthquake. These travel faster than the actual surface waves, so they can give some advance warning of shaking. The farther away you are from the epicenter, the earlier the warning reaches you before the shaking starts at your location. 

Like you, this is the first time I've received such a warning, and my immediate reaction was "huh?" By the time my reaction of surprise was over, the shaking started, so no real time to react. It's a small island, so I doubt this system will ever be that useful here for earthquakes generated on the actual island, but it's better than nothing. 

There's a decent summary of the system here - https://scienceexchange.caltech.edu/topi...ng-systems

[TomK]

The USGS now does the same digitally, which helps those with automated systems that would be better being offline when struck.

What do you mean by that? It makes little sense to me

[randomq]

Observatories?
https://arxiv.org/abs/1412.3603
Early earthquake warning is a rapidly developing capability that has significant ramifications for many fields, including astronomical observatories. In this work, we describe the susceptibility of astronomical facilities to seismic events, including large telescopes as well as second-generation ground-based gravitational-wave interferometers.

Other stuff:
https://www.weir-jones.com/real-time-ear...detection/

• Elevators can stop at the nearest floor.
  
• Gas lines can close to prevent fires.
  
• Trains can slow or stop.
  
• Industrial equipment can shut down safely.
  

I could see it being used to park hard drive arrays in data centers too.  A momentary blip in latency to prevent data loss.

[HereOnThePrimalEdge]

I didn’t read about much if any damage from the quake in Puna, but west side residents and farmers lost many catchment tanks:

By Monday morning, Yeaton had already received “well over 100” phone calls from Kona farmers and other rural residents.

“Most people’s tanks blew out catastrophically,” he said. Some tanks collapsed, many others had their linings torn. The linings are typically attached to the ground beneath the tanks, and they stayed attached while the tanks themselves, he said, “walked for up to a foot” in the quake.

https://www.civilbeat.org/2026/05/kona-e...-hundreds/

[TomK]

Observatories?
https://arxiv.org/abs/1412.3603
Early earthquake warning is a rapidly developing capability that has significant ramifications for many fields, including astronomical observatories. In this work, we describe the susceptibility of astronomical facilities to seismic events, including large telescopes as well as second-generation ground-based gravitational-wave interferometers.

That was a 2014 paper. A lot has been done since then. The recent earthquake temporarily shut down the MK observatories, but I'm not aware of any data being lost other than data that couldn't be taken after the event. I don't know how you mitigate for that. On our side, everything shut dot down as planned and made the observatory safe. I think every other MK observatory did the same thing. There was certainly a lot of chatter between the observatories, but that's part of how the MK observatories cooperate.