Tsunami Alert!

There was a large earthquake last night!

Did you feel it? Probably not. It was all the way in Alaska!

Our seismometers felt it! When earthquakes occur, they release a lot of energy. This energy shakes the ground, which we feel. More than just the Earth's surface is shaken, though. Earthquakes also cause waves inside the Earth too. If the earthquake is large enough and our instruments are sensitive enough, these waves can be felt around the world. Last night's earthquake was so large that our instruments in schools across Aotearoa felt the seismic waves (earthquake waves).

Looking at the screenshot below, do you see how the waves on the seventh line are larger than almost all of the preceding lines? See how the continue to grow on the eighth line? these are the waves from the Alaska earthquake reaching Aotearoa.

But I said the earthquake was last night, and the top of line of this dataset is from midnight to 1 AM... and the seventh line is labelled 6 AM and stretches to 7 AM. That's not last night.... What's going on?

Well, there are a few things going on. First, seismologists (scientists who study earthquakes) use the UTC time zone. UTC stands for Universal Time Coordinated. This is the time zone in Greenwich, United Kingdom. The times being shown on the data above actually aren't the current time in Aotearoa. Second, seismic (or earthquake) waves travel quite fast, on the order of kilometers per second. Alaska is a very far away though! I'm currently more than 11,000 kilometers away. Even at kilometers per second, it will still take a while for seismic waves to reach me! In fact, it took around 12 hours for us to start sensing the Alaskan earthquake here in Aotearoa.

The data we are showing you above is from Rodney College's Rū, which is their in school seismometer. Do you want to watch for earthquakes in your school? Get in touch with us to see if we can make your dream possible.