Although Hawke's Bay doesn't have any volcanoes, the area has been affected by over 20,000 years of volcanic activity, mainly in the form of ash falls.
Mount Ruapehu (1995)
Massive eruptions can cause a volcano to collapse in on itself and form a caldera. This is what happened at Taupo. The lake is a caldera that filled with water after one of the largest volcanic explosions in human history about 1800 years ago.
With the nearest volcano about 100 km away, Hawke's Bay has been spared the worst effects of an eruption. However, because a westerly is a prevailing wind in the North Island, Hawke's Bay is vulnerable to volcanic ash falls and their associated hazards when eruptions occur in the Taupo and Central Plateau regions.
Hawke's Bay peat bogs, swamps and road cuttings record a complex sequence of ash layers from Taupo, Okataina (the area between Rotorua and Kawerau), Ruapehu and Taranaki volcanoes that date back over 20,000 years. Scientific research has determined that eruptions from the Okataina and Taupo volcanic fields could produce sufficient volcanic ash to significantly impact on Hawke's Bay. Large eruptions from Ruapehu, Tongariro, Ngauruhoe and Taranaki would likely be less impactful. Ash falls from Ruapehu in 1945, 1975, 1995 and 1996 affected this region, as did Tongariro in 1896. Eruptions from White Island, in the Bay of Plenty, and other volcanoes are not likely to affect Hawke's Bay.
Have facemasks at the ready – large handkerchiefs or scarves are a reasonable substitute. Know how to disconnect any roof-fed water supply when an ash fall warning is given or ash begins to fall.
During an ash fall
After an ash fall
For a booklet and further details on the guidelines and preparedness before, during and after an ashfall go to www.ivhhn.org