▁The ▁North ▁Island ▁of ▁New ▁Zealand ▁has ▁w ides p read ▁back - arc ▁vol can ism ▁as ▁a ▁result ▁of ▁this ▁sub du ction . ▁There ▁are ▁many ▁large ▁vol cano es ▁with ▁relatively ▁frequent ▁er u ptions . ▁There ▁are ▁also ▁several ▁very ▁large ▁cal der as , ▁with ▁the ▁most ▁obvious ▁forming ▁Lake ▁T au po . ▁T au po ▁has ▁a ▁history ▁of ▁incred ibly ▁powerful ▁er u ptions , ▁with ▁the ▁O ru an ui ▁er u ption ▁▁ 2 6 , 5 0 0 ▁years ▁ago ▁e ject ing ▁ ▁of ▁material ▁and ▁causing ▁the ▁down ward ▁collapse ▁of ▁several ▁hundred ▁square ▁kilometres ▁to ▁form ▁the ▁lake . ▁The ▁last ▁er u ption ▁occurred ▁ ▁and ▁e ject ed ▁at ▁least ▁ 1 0 0 ▁cub ic ▁kilometres ▁of ▁material , ▁and ▁has ▁been ▁correl ated ▁with ▁red ▁sk ies ▁seen ▁at ▁the ▁time ▁in ▁Rome ▁and ▁China . ▁The ▁associated ▁ge oth erm al ▁energy ▁from ▁this ▁vol can ic ▁area ▁is ▁used ▁in ▁numerous ▁hydro ther mal ▁power ▁plants . ▁Some ▁vol can ic ▁places ▁are ▁also ▁famous ▁tour ist ▁destin ations , ▁such ▁as ▁the ▁Rot or ua ▁ge ys ers . ▁ ▁The ▁sub du ction ▁direction ▁is ▁revers ed ▁through ▁the ▁South ▁Island , ▁with ▁the ▁Ind o - Austral ian ▁Pl ate ▁forced ▁under ▁the ▁Pacific ▁Pl ate . ▁The ▁transition ▁between ▁these ▁two ▁different ▁styles ▁of ▁contin ental ▁collision ▁occurs ▁through ▁the ▁top ▁of ▁the ▁South ▁Island . ▁This ▁area