Tag Archives: geology

Gerringong – Part 1

I like the Illawarra coast, and last week I got to visit the seaside town of Gerringong. Gerringong has always been the smaller brother of Kiama, a few k’s up the coast, but with the coming of the by-pass it’s about to get very big. I’m glad that I made this visit before it changed for good.

We took a little walk along the relatively new Kiama to Gerringong Coast Track to the other side of Red Cliff. Walking along the shoreline, Hubby told me that the cliff was made up of Permian aged sandstone, rich in iron (hence the red).

Werri Beach

Meanwhile, the rock platform below was made up of black basalt, meaning that there was volcanic activity here at some stage. Other local landmarks such as Bombo and the Blowhole are also made of basalt. It’s spectacular when the swell is up.

Werri Beach

Taupo

Down the road from Rotorua in Taupo, they make use of the geothermal energy by building powerstations.

Taupo Geothermal Power Station

The raging Waikato river (shown below at Huka Falls), means that there are also hydroelectric power stations too.

Huka Falls

Huka Falls

One needs only to look at the vastness of Lake Taupo, the result of a supervolcano eruption, and whose vast caldera is still active underground, to know that there’s certainly energy available, but if that volcano was to erupt again, then we’d all be in big trouble.

Lake Taupo

Lake Taupo

Rotorua – Part 2

Aside from geysers, there were plenty of geothermal attractions all over the place. In some places you really did need to watch where you were going lest you fall into a pool of hot, acidic mud.

Wai-o-tapu

Hell's Gate

The mineral rich pools came in all shades, no food colouring involved.

Wai-o-tapu

Wai-o-tapu

Wai-o-tapu

In other places, the landscape created by all of this turmoil was very pretty.

Hell's Gate

Waimangu

There were plenty of stories told by our various guides, particularly from the 19th Century when a local volcano, Mount Tarawera, erupted, destroying much of the area and killing many people. It could happen again, and soon. Despite this, Rotorua is one of the North Island’s bigger towns being a centre for forestry, energy and tourism. It goes to show that the locals must be hardy types.

Hell's Gate

Rotorua – Part 1

Next we explored the geothermal wonderland that is Rotorua. Seeing a geyser come into life is a good introduction of what’s underneath the city. The Lady Knox Geyser erupts every day at 10.15am, with a bit of human intervention.

Lady Knox Geyser

From then on it took a couple of minutes to bubble up.

Lady Knox Geyser

Lady Knox Geyser

And then burst into life.

Lady Knox Geyser

Lady Knox Geyser

Not a bad start to the tour. Certainly don’t see anything like this in Australia.

White Island – Part 3

We turned back from the crater to walk back to the beach. The blue sky and sea made a dramatic contrast to the crater.

Day trip to White Island

Day trip to White Island

Near the beach, we visited the remnants of the old sulphur mine. At the turn of the 20th Century, some very hardy souls tried to mine the deposits of yellow sulphur. Sulphur was used in medicines, as sterilisation, in match heads, and in fertiliser, so they thought there was a buck to be made.

Day trip to White Island

Day trip to White Island

Living on a volcano had its downsides. Food and water had to be brought to the island, however since the Bay of Plenty was frequently rough, supplies weren’t guaranteed. The air quality (as we found out) wasn’t great, and the sulphuric acid ate away at everything. But most crucially, a hundred years ago they didn’t have seismic monitoring and so when part of the rim collapsed in 1914 creating a lahar (a mudflow made up of volcanic material and water) the 10 workers on the island didn’t have a hope. The only survivor was the camp cat, Peter, which was found a few days later. He was appropriately renamed ‘Peter the Great’ and became a local celebrity.

Day trip to White Island

Day trip to White Island

They had another go at mining a few years later, but the amount and quality of sulphur wasn’t great and so mining was abandoned; the buildings and equipment left to corrode in the sulphuric fumes.

Day trip to White Island

We returned to the boat, and on the way back to Whakatane passed by a New Zealand fur seal colony nearby. At least these guys can get away quick smart if the volcano gets twitchy.

Day trip to White Island

The boat sped off back to land, and soon the volcano was once again steaming away in the distance. This was one adventure we won’t forget in a hurry.

Day trip to White Island

White Island – Part 2

We left the relative comfort of the boat and stepped on to a moonscape. This was the earth at its most raw, how it must have looked when it was first born.

Day trip to White Island

Day trip to White Island

Day trip to White Island

All around us were piles of rocks (some of startling hues due to its mineral content), steaming vents, and bubbling mud pools. We were given gas masks as the sulphire dioxide (that stinky egg smell) was sometimes overpowering. We really had to follow our guides carefully as none of us wanted to drown in a pool of hot acid.

Day trip to White Island

Day trip to White Island

Day trip to White Island

The most impressive site was the steaming vent, or series of vents. Even though the steam was caused by seawater pouring into the hot crater and something more noxious, it was still frightening. It was like peering into the depths of hell.

Day trip to White Island

Day trip to White Island

White Island – Part 1

Our visit to White Island was certainly the highlight of the tour. White Island is an active volcano 50km off the coast, in the middle of the Bay of Plenty. There’s not that many places on earth where you can step into the crater of a live volcano so everyone on the tour was excited.

It was an early, pre-dawn start, with breakfast at 5.15am so we could reach the Bay of Plenty town of Whakatane, our departure point. The sun was just rising when the boat passed the sandbar.

Day trip to White Island

Day trip to White Island

The coast was soon behind us as we cruised into the middle of the bay.

Day trip to White Island

Day trip to White Island

It was a bit chilly on deck, but being very prone to seasickness, I’d rather be there than indoors. Luckily the weather was good and the water was quite calm.

Day trip to White Island

We first caught sight of the island about an hour or so into the journey. And the volcano was steaming!

Day trip to White Island

Day trip to White Island

Day trip to White Island

We arrived at the hour-and-a-half mark. With some trepidation, we boarded the rubber zodiacs and approached the island.

Day trip to White Island

What did we find?

Auckland – Part 2

We travelled from east coast to west coast in a few hours in Auckland to view some volcanic features. On the calm waters of the east coast at Takapuna Beach, we saw Rangitoto Island, a volcanic that erupted only 500 years ago.

Around Auckland

The sand on this beach is sandy at least, and full of shell bits. It’s not a bad place to stroll down, even on a showery day.

Around Auckland

The west coast beaches of course were completely different. We visited Muriwai Beach to view the basalt columns on the cliff-face.

Around Auckland

With its black sand, biting winds and roaring surf, it was certainly a wild and woolly place.

Around Auckland

Auckland – Part 1

A few weeks after we returned from Europe via Singapore, we packed our bags again. Hubby was leading a 10 day geology school group tour of the North Island of New Zealand, and I once again tagged along.

Around Auckland

It was mid-winter, and Auckland was a bit chilly, although nothing like what it had been in Europe, and showery. We started off by visiting Mt Eden and its extinct volcano crater. Auckland is full of these extinct craters, although these volcanoes oozed rather than exploded.

Around Auckland

In the distance we could see other ‘mounds’, which were other volcanoes. Nowadays they are surrounded by suburbia. Luckily they are well and truly extinct!

Around Auckland