The violent 1886 eruption of Mt Tarawera changed the surrounding landscape in an instant. Photo / Creative Commons image by Flickr user Krzysztof Belczyński
The violent 1886 eruption of Mt Tarawera changed the surrounding landscape in an instant. Photo / Creative Commons image by Flickr user Krzysztof Belczyński
The recent Kaikoura earthquake ripped chasms into the countryside and destroyed a seal colony - here are some other NZ places where earthquakes or volcanic activity have changed the landscape forever.
Parts of the northern South Island were dramatically altered in last month's magnitude 7.8 earthquake, with uplift of 6 metres in some areas along the east coast and a huge fracture appearing along the Kekerengu Fault (see video below), but this isn't the first time New Zealand's landscape has been drastically altered by natural phenomena.
Here are some other New Zealand places where earthquakes or volcanic eruptions changed things forever — sometimes in an instant.
Stewart's Cave in Mt Roskill is one of the many lava caves hidden beneath Auckland's suburbs. Photo / Creative Commons image by Flickr user Paul Rowe
Built as it is on a volcanic field, Auckland has its fair share of sites shaped by natural processes. Caves and tunnels created by past lava flows can most easily be explored on Rangitoto, but dozens are also hidden beneath central and south Auckland suburbs. Many of them are on — or under — private land but geological societies sometimes run field trips enabling members of the public to explore these subterranean marvels.
Of course, the volcanoes that were responsible for all these lava flows are also well worth a visit. Some of Auckland's volcanic cones have been completely quarried away, but those still dotted across the city are reminders of the landscape's violent origins.
Fossilised forests
Another way volcanic eruptions have altered the landscape is by smothering ancient forests with mud, ash and lava. Over time, the buried trees either burned and rotted away, leaving hollow moulds in their image in the surrounding rock (in the case of lava flows) or became petrified (turned to stone) under the layers of sediment. In some places, where sufficient erosion of the deposited landscape has taken place, the fossilised forest remnants can once again be seen. Some of the best examples of this in New Zealand are at Ihumatao on the shores of the Manukau Harbour, along the North Shore coastline between Takapuna Beach and Thorne Bay and at Southland's Curio Bay.
Ancient petrified forest on the coast at Curio Bay, Southland. Photo / 123RF
Maruia Falls, Tasman
One place where the ongoing effects of a past event can be seen is at the Maruia Falls, which didn't exist prior to the magnitude 7.8 Murchison earthquake of June 17, 1929. The quake caused tremendous upheaval throughout the region and landslides blocked many rivers in the area, including the Maruia, which subsequently diverted itself further west and began cutting a new course over an old river bank.
The Maruia Falls, southwest of Murchison, were created when a landslide triggered by the 1929 earthquake forced the river to divert its course. Photo / 123RF
As the redirected river gradually eroded the gravel bank, a waterfall began to form and it's continued to grow in size ever since. Immediately after the earthquake the drop was around one metre but the falls now splash down 10 metres.
A painting by Charles Blomfield of the white terraces as they looked prior to the 1886 eruption of Mt Tarawera. Photo / Supplied
Probably the most well-known local example of changes wrought by the might of the earth is the eruption of Mt Tarawera on June 10, 1886. One of this country's earliest tourist attractions, the famed Pink and White Terraces, were thought to have been completely destroyed in the eruption, though recent research has
far below the surface of Lake Rotomahana. The present-day lake, which is only a few kilometres southwest of Mt Tarawera, was a much smaller body of water prior to the eruption.
Steam rises from the cliffs at the edge of Rotorua's Lake Rotomahana. Remnants of the Pink and White Terraces have been found beneath the lake's surface. Photo / Creative Commons image by Flickr user JSilver
Evidence of the explosion's devastating power can also be seen at Te Wairoa, a former village west of Lake Tarawera which was one of a number of settlements that bore the brunt of the eruption's fallout. Somewhere in the region of 150 people are thought to have died in the disaster, making it New Zealand's most deadly volcanic eruption to date.
The village of Te Wairoa after the Tarawera eruption of 1886 blanketed it with mud and ash. Photo / Supplied by Destination Rotorua
Amid the destruction however, a new geological region to explore opened up. The eruption created a vast chasm now known as Waimangu Valley, an area crammed with fascinating geothermal activity. Its simmering Frying Pan Lake is one of the largest hot springs in the world and miniature silica terraces have begun to form once again.
Silica terraces at Waimangu Valley in Rotorua. Photo / 123RF
The Basin Reserve, Wellington
One of New Zealand's best-known sports grounds wouldn't exist — at least not in its current location — had it not been for the huge earthquake that rocked central New Zealand on January 23, 1855. Prior to the magnitude 8.2 quake, the area was the site of a swamp and there were plans to connect it to the sea via a canal in order to create an inner-city harbour. All that changed when the earth violently moved — uplifting much of present-day Wellington's CBD as well as the site now known to cricket fans the world over as The Basin Reserve.
Wellington's Basin Reserve: Prior to the earthquake of 1855, a lake occupied this area and it was earmarked to become an inner-harbour. Photo / Creative Commons image by Wikimedia user PaddyBriggs
Waipatiki Beach, Hawke's Bay
Much of Hawke's Bay shifted in the powerful earthquake of February 3, 1931 — Napier Airport is built on the site of the former Ahuriri Lagoon, which was uplifted during the shaking, as was the foreshore along Marine Parade — but there's another picturesque site which was monumentally altered on the morning of the quake . . . Waipatiki Beach, about 30km north of Napier.
The magnitude 7.8 earthquake which wrought so much destruction in the city was centred just off the coast of Waipatiki, an estuarine valley area of mud flats which was a rich source of flounder for early Maori inhabitants. During the quake, those bountiful flats were raised above sea level and a stream system appeared.
The mud flats of the estuarine valley at Waipatiki were uplifted during the Hawke's Bay earthquake of 1931. Photo / Eveline Harvey
Today, the area is a popular summer holiday spot with a flat, sandy beach flanked by crashing surf on one side and the stream on the other. The steep limestone headlands at either end of the beach hold a wealth of fossilised treasures for walkers to investigate and visitors can stay right at the beach if they so desire: the Hawke's Bay Regional Council, Napier City Council and Hastings District Council recently joined forces to purchase the Waipatiki Beach Holiday Park, which many had feared would be sold to developers.
