Newswire data

How big were Taupo’s past eruptions?

Pick an eruption to see its likely pyroclastic flow zone and ash isopachs draped over the North Island. Real ash deposits are blown downwind — here, east-northeast under New Zealand’s prevailing westerlies.

What you’re looking at. Pyroclastic flow zones are drawn as circles centred on the vent — in real life they follow valleys and slopes, but the radius is a reasonable cartoon of the kill zone. Ash zones are ellipses skewed east-northeast to reflect prevailing westerlies; the lobed shape mimics the isopach maps published by GNS Science and the volcanological literature (Wilson & Walker, Self & others). Volumes and reach are rounded to make the comparison legible — do not use these polygons for engineering or planning purposes.