Day 46 - Volcanic Valley and Mount Maunganui, Bay of Plenty, North Island, New Zealand

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Friday January 3rd, 2014. Volcanic Valley and Mount Maunganui, Bay of Plenty, North Island, NZ

After breakfast we jumped back in the car and returned to WOT. The reason for this is that our ticket from yesterday included a visit to the Lady Knox Geyser which spouts every morning at 10.15 am. We had to leave by 9.00 in order to make sure we were there in time for this daily event. This geyser is not in the main body of WOT, it is located up the road down a side track. We arrived and joined hundreds of others in the queue to park and then made our way through the entrance to the geyser.

It was laid out like an auditorium with terraces of seating in a semi-circle around the main attraction, the geyser, which was like a small white volcano of silica about 5 feet high. We kept looking at our watches and then expectantly at the little volcano as 10.15 came and went. Well, we supposed you can't expect nature to be exactly on time to the second! At about 10.30 a guy appeared standing next to the geyser with a microphone and a small packet. He informed the expectant crowd that in the mid 19th century this geyser wouldn't have appeared like it does now as a mound of white silica - it would simply have been a flat pool of hot water. The pool was discovered by some forestry workers who thought it would be a good place to wash their clothes - much better than heating up loads of buckets of water. When they added the soap to clean their clothes the geyser spouted sending the clothes in the air and leaving the men to flee into the bush starkers. Then he took his little packet and explained that it contained soap crystals (environmentally friendly ones of course!). The science behind this is that the soap upsets the surface tension in the water and causes the geyser to spout (we had really believed that this was all a natural phenomenon!). He proceed to tip the contents of the packet into the crater of the little white volcano. Nothing happened immediately and he stood there, right next to the geyser, and explained that it was impossible to tell how long she would spout for or how high the spout would be.

Water started to bubble out of the volcano crater and trickle down the slopes and then it got a little more excited and bubbled up about a foot high, then whoosh off it went. She spouted to about 30 feet (10 metres). D got some snaps from different angles and she was still spouting when we left and returned to the car. It had been quite a spectacle but we both felt cheated (and a little stupid for believing it was all down to nature) that it was not a natural event at all. It is artificially induced every day at about 10.30 am and has been since the 1980's. It is this constant spouting that has caused the little volcano of silica to build up. Still we are glad we got up and made the effort to go and see it - artificial or not.

Back in the car we drove back towards Rotorua and turned off right for the Waimangu Volcanic Valley. This is the world's youngest Geothermal System. The landscape here is volcanic scenery and pristine geothermal sights in craters formed on 10th June 1886. It is the only geothermal Eco-system created as a direct result of a volcanic eruption. It also contains the only NZ example of a native forest re-establishing itself from complete devastation. In 1886 the Tarawera Vocano erupted, 22 craters exploded and for 17 kilometers around all life was extinguished.

Between 1900 and 1904 the Waimangu Geyser erupted roughly every 36 hours. It was the largest ever Geyser that blasted boiling water, rocks, sand an steam up to 400 metres into the air. In 1917 Frying Pan Flat exploded. Within 2 weeks the resulting crater was filled with hot spring water and became Frying Pan Lake - the largest hot water spring in the world. The 1886 volcanic eruption punctured the area with a series of craters and allowed geothermal fluid already present underground direct passage to the surface of the Earth. Since the time of their formation developments new geothermal features have been recorded. Tawawera volcano and the craters of the Waimangu Volcanic valley lie along one of the earth's great fractures above the Pacific and the India/Australasia tectonic plates which is the reason for all this volcanic activity.

We parked and went to the ticket office. There were a number of different options available, walk only, a walk combined with a boat trip on Lake Rotomahana or just cruise on the boat. We opted for walk only and paid our entrance fee. We were given a map of the route and the nice lady explained that there were 3 bus stops. This meant that we could walk just to stop one and come back, or come back at stop 2 or do the whole walk, the last section of which is a nature trail to the lake with no geothermal stuff to look at. D asked the nice lady if we could catch the bus to the end and walk back. She advised against this as it is all uphill in that direction. So off we went - in the downhill direction!.

The route consisted of numbered items and the map contained an explanation corresponding to each number. The first thing we came to was a viewpoint which gave us a fantastic panorama of the valley. Dominant on the skyline is the Tarawerea volcano which has erupted 5 times in the last 18,000 years. In the foreground we could see the Waimangu Valley. Before the eruption in 1886, the area we could see was rolling scrub-covered hills with no surface hydrothermal activity. During the aforementioned eruption a line of craters from the northern end of Tarawera all the way to the Waimangu Valley was formed. This event completely destroyed all plant, animal and bird life in the whole of the area that we could see below us. All the vegetation that is here now has resulted from plant re-colonization since then.

We continued down the well marked trail until we came to the Southern Crater which is the southern-most crater formed by the 1886 eruption. It is about 50 metres deep and has not been active since immediately after that initial eruption apart from having some warm ground and a couple of small mud pools at its North-East end. The shallow lake (aka Emerald Pool) is filled with cold water.

We crossed over the ridge of land between the Southern Crater and the adjoining valley (The Saddle). The blurb told us that this walkway dates back to 1917. We were now next to the Emerald Pool. It colour is caused by the huge mats of algae and sphagnum moss in the water. The native red floating fern Azolla is apparently also sometimes present in the lake.

The trail took us past some eruption deposits formed by the 1917 eruption from Echo Crater. Nowadays Frying Pan Lake occupies the floor of that crater. The deposit is typical of those produced by steam eruptions containing everything from clay to large boulders. From here we had wonderful views of Echo Crater and Frying Pan Lake. Echo crater was formed in the 1886 eruption and has been the site of many volcanic activities since then, including the Waimangu Geyser eruptions from 1900 to 1904, April 1915 and April 1917.

40 meters further along the track, at the Frying Pan Lake lookout, the blurb told has that on 1 April 1917 the western basin of Echo Crater violently erupted. This eruption completely destroyed a house and killed two people. The resulting deepened, and enlarged, crater quickly filled with water and formed Frying Pan Lake, The lake covers 38,000 sq metres which makes it the world's largest hot spring, with an average depth of 6 metres and average temperature of about 131 degrees F or 55 degrees C. We could hear the eerie sounds coming from the hot springs and fumaroles in the crater and lake. The lake water is very acidic with carbon dioxide and hydrogen sulphide gas bubbling to the surface which makes it look like it is boiling. We came to the next number on the map which marked the site of the 1973 Trinity Eruption. The blurb told us that the bubbling area about 10 metres from the shore of the lake below us was the site of an eruption in February of the 1973. Mud from this 15 minute eruption was sprayed over an area more than 100 metres across. The Trinity eruption was one of the largest to occur at Echo Crater since 1917. It is also the most recent.

We passed a wall of fragile sulphur and sulphide crystals until we reached the Cathedral Rocks. These were originally named Gibraltar Rock because of thier resemblance to the historic rock in the Med. The shape of this steaming monolith was altered by the Frying Pan Flat eruption (1917) and its residual pinnacles were renamed. It is comprised of rhyolitic lava at least 60,000 years old - much older than the Tarawera Volcano.

We next came to the point where we could see the basin where the Waimangu Geyser used to be. Only active for 4 years (1900-04) this was the world's largest known geyser. sometimes erupting up to 400 metres (1300 feet), hurling black sand, mud and rocks into the air. It followed a 36 hour cycle of activity (really - not induced by soap powder!).

We walked past Hot Water Creek and Springs which is where the Frying Pan Lake overflows through a notch at a temperature of 50 degrees C. Minerals have been deposited which, along with the blue green algae form spectacular orange, brown green an yellow colours along the edge and around the springs. There was also a cluster of vigorously boiling hot springs building intricate and beautiful silica formations. Up to our right we could see a white cross on the lowest point of the crater rim. This marks the site where 4 tourists were standing (even though they had been warned it was dangerous) in order to see the Waimangu Geyser. They were washed to their deaths in August 1903 when she erupted very suddenly.

Proceeding along the track we came to Te Ara Mokoroa Terrace (Long abiding path of knowledge). These are a series of silica terraces that have been created by 'Spring N' which suddenly sprang to life in 1975 as a small erupting spring. We continued along to the Inferno Crater Overflow Channel. We hadn't seen the Inferno Crater yet as it was at the top of a steep climb up some steps. When Inferno Crater overflows, near boiling water cascades down this small valley, swelling the hot stream we had just walked past. The temperature of the water is so hot it kills the blue-green algae which had grown on the floor of the channel between times of overflow.

Next we climbed the steps up to the Inferno Crater Lake. This steaming pale blue jewel of Waimangu lies in an 1886 crater blown in the side of Mount Hazard. The lake level follows complicated rhythmic cycles with shallow recessions occurring every few days and/or deeper recessions at longer intervals. The top of the white silica deposit marks the overflow level. Commonly it overflows for 2-3 days recedes about 8 metres for some 15 days, partly refills over 3-4 weeks, oscillates for a while and then overflows again. Inferno Crater is the largest geyser-like feature in the World, although the geyser itself cannot be seen as it plays at the bottom of the 30 metre deep (when full) lake. It has a unique relationship with Frying Pan Lake, in that when it is overflowing there is a decrease in the discharge from Frying Pan Lake, and when it is receding the discharge from Frying Pan Lake is greater than normal. This was the best bit so far as far as M was concerned. A nice couple took a picture of us together with the lake in the background.

After descending the steps we had a bit of trouble finding the next number. This was Bird's Nest Terrace where striking milt-coloured algae stick to the delicate miniature silica terraces formed by the boiling springs we saw back down the track. The different colours are caused by the varying temperature in the overflow from the springs. Apparently you won't see any blue/green if the temperature reaches more than 75 degrees C. Following the path the next number was Clamshell Spring. Here the silica rich waters of this boiling spring form an unusual shell-shaped terrace (we couldn't see it!) which helps to maintain the adjacent stream temperatures. These springs are home to thermophilic bacteria which are believed by many scientists to have been present at the beginnings of life on earth. Oh how we love this! Our boats are reeling!

Next we saw some 'silica stalactites' - not very impressive to look at but we took a snap anyway. These have been formed from dripping and trickling mineral rich water in a similar way to limestone stalactites. The ones we could see had been formed by hot water percolating out of Mount Hazard since Waimangu Geyser stopped erupting.

We had now reached Bus Stop 1 - but had no intention of going back as we were enjoying ourselves too much. We really felt like we were the first people to see all this magical stuff. It was so noncommercial - not at all like WOT. The next number was some buried soil. We read the blurb but didn't get it at all so went to the next one which was a Kaolin (China Clay) slope. Continuing on, we apparently were at a point where hot and cold streams meet - though you couldn't tell. We passed a section of track where you could clearly see the different soil layers showing the recent geological history of the valley. More hot springs followed until we came to Bus Stop 2. We walked past the stop to go to the loo where there was the last (and one of the best) of the geothermal stuff. Number 27 was the Marble Terrace and Buttresses. These have been formed by silica depositing out of solution, and building successive layers,over a period of time. The silica rich water is supplied from a large hot spring called Iodine Pool (named for its colour on the rocks and banks). The water leaves Iodine Pool at a temperature of 97 degrees C to flow across Marble Terrace in shallow waves. Marble terrace and its buttresses are growing over a stream terrace formed when Lake Rotomahana was at a higher level in the 1970's and the stream is frequently flooded here.

We walked back to Bus Stop 2 and got on the next bus to Stop 3. Here we took a few snaps of the lake and the re-boarded the same bus back to the car park. This was M's favourite geothermal stop as it is totally unspoiled and natural - D still preferred WOT.

Once back in the car we drove back to Rotorua where we got some petrol (gas) and then continued to our next destination which was Tauranga on the Bay of Plenty. This bay is a long stretch of beautiful white sand beaches lining the coastline and is great for all water-sports. Tauranga is the Bay of Plenty's main centre and has one of NZ's fastest growing populations - so it must be either popular or boring. Wine is also made in this area. On the drive we saw bountiful orchards, lots of road side stalls selling Avo's (Advocado Pears) an all sorts of other fruit. Apricots seem to be in season - hence the name "Bay of Plenty".

We checked in to the YH and did some shopping before heading off to Mount Maunganui. This is one of the North Island's main holiday spots. It has a gorgeous white sand beach, good surf and all the other stuff (restaurants, bars, shopping etc) which go with a holiday resort. Overlooking the town is Mauao (Mount Maunganui) an extinct volcano. The volcano's iconic cone-shaped mountain, Mauao, stands proudly above the resort. We parked at Pilot Bay and then walked around the base of the volcano. It was a great stroll and the scenery was amazing. It was a circular walk so we ended up walking through a really busy campsite back to the car.

There is a rather lovely Maori myth relating to Mauao. Mauao was once a nameless inland mountain that fell in love with another (female of course) mountain who was not interested. Mauao was so upset that he asked his night owl fairy friends to drag him to the Pacific Ocean where he intended to drown himself because of his grief. He was dragged as far as the end of the peninsula when the sun came out and his fairy friends buggered off leaving him stranded forever. Mauao means "caught by the dawn" in Maori.

Back to the YH, good dinner and bed. Lots planned for tomorrow.

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