Weak zones

Using thunderquakes to X-ray Earth – a new study shows urban seismology in action

<figure><img src="https://images.theconversation.com/files/755379/original/file-20260821-50-d6mpg6.jpg?ixlib=rb-4.1.1&rect=0%2C0%2C4242%2C2828&q=45&auto=format&w=1050&h=700&fit=crop" /><figcaption><span class="caption">As lightning lights up apartment buildings, the thunder creates useful vibrations.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/lightning-strikes-illuminate-the-sky-above-a-residential-news-photo/2279501390?adppopup=true">Philip Fong/AFP via Getty Images</a></span></figcaption></figure><p>When lightning strikes, it superheats the air around it and <a href="https://www.noaa.gov/jetstream/lightning/sound-of-thunder">creates a shock wave</a> that we hear as thunder. But thunder doesn’t just travel through the atmosphere to our ears.</p> <p>When that energy reaches the ground, some of it is converted into seismic waves that ripple through the soil and rock beneath. The resulting vibrations are