Nature already has an early-warning system. We're building the receiver.
In 2004, elephants on the Andaman coast climbed to higher ground minutes before the wave came in. Birds clear out a day ahead of a big storm. What they're catching is infrasound: pressure waves under 20 Hz that carry for hundreds of kilometres. Scientists have measured it for decades. Hardly anyone is listening for it right at the coast, which is the one place a few minutes of warning changes the outcome.
That gap is our job. We make low-cost acoustic tools that help people hear trouble sooner — earlier warning for tsunamis and eruptions, protection for the coastal infrastructure life depends on (power-plant and desalination intakes, aquaculture), and a way to keep people and wild animals apart without nets, poison or harm. All of it is open, and we try to be plain about what already works and what we're still figuring out.
The longer view: as the network grows — cheap sensors spread densely, anchored by a few precise reference stations — HERD becomes an open platform for the whole research community. A place where scientists anywhere can develop and, just as important, reproduce and confirm new methods: signal-processing algorithms, machine-learning models, studies of atmospheric and geophysical processes, and new ways to catch dangerous events earlier. The instrument is a public good — and the discoveries made on it can be too.
