diaries/diary-4 from earthscience91. http://earthscience91.learnz.org.nz/index.php?vft=ear... Previous Darren's Diaries for West Coast Earth Science Diary 4 - Friday 13 March 2009 Field Trip Name: West Coast Earth Science Field Trip Place: Stockton Diary number of total: 4 of 4 Weather: Blue skies for most of the day Where's Darren: Travelling across the Southern Alps (Westport- Hanmer Springs) Hi everyone, Darren here. Low cloud in the Buller Gorge this morning. Image: Heurisko Ltd. We left Westport as the Sun was rising this morning. Heading inland up the Buller River we were met by the sight of low cloud rolling down the gorge towards us. It reminded us of the glaciers that flowed from the hills in this area a few thousand years ago. Our first stop today was the little town of Inangahua Junction. Before 1968 not many people had heard of the place but that all changed at 5.24am on the morning of 24 May 1968. Movement of a fault just a few kilometres to the north of the town caused a magnitude 7 earthquake. Buildings were destroyed by the shaking and by landslides from the surrounding limestone hills. It was a while before the rest of New Zealand knew of the damage as communications to the area were cut. Numerous Inside the musuem at Inanaghua Junction. Image: Heurisko Ltd. aftershocks continued, with a further 14 greater than magnitude 5 that same day. A pilot of a rescue helicopter said he saw the ground "moving like waves" as he flew over the area during one of these aftershocks. Three people died during the earthquake and another three died when a rescue helicopter crashed. We spent some time in the small museum there looking at the photographs and reading the newspaper reports of that day. Driving east we followed the Buller River to Murchison. Along the way we spotted a huge part of the ridgeline above us that had been dislodged in another earthquake, the Murchison earthquake. The year of 1929 was a year of earthquakes in New Zealand, 678 in total. Large earthquakes happened in Arthur's You can see where a large part of the ridgeline collapsed during the Murchison Pass (9 March) and the Central North Island (8 May) but these earthquake. Image: Heurisko Ltd. were overshadowed on Monday 17 June. At 10.17am a magnitude 7.8 earthquake shook New Zealand from Auckland to Dunedin and was centred on Murchsion. The 300 people who lived there were thrown to the ground as a piece of land 75km long was lifted by about half a metre. Witnesses spoke of the noise the earthquake made, a booming sound heard as far away as Taranaki in the North Island. Roads rippled like ribbons being blown by the breeze. Seventeen people died, many due to the landslides and floods the earthquake caused. There is a monument to these people outside of the small museum in Murchison. The names of the people have been put on rocks from the landslides that took their lives. Take a look at the photo The memorial in Murchison to the 17 people who taken just after the earthquake to get an idea of the devastation. lost their lives in the 1929 earthquake. Image: Heurisko Ltd. We headed south to visit another product of the Murchison earthquake, Maruia Falls. Take a look at the panorama image to 1 of 3 15/06/2009 16:35 diaries/diary-4 from earthscience91. http://earthscience91.learnz.org.nz/index.php?vft=ear... see this waterfall on the Maruia River created when the earthquake caused a landslide which altered the course of the river. Back in car the we continued our journey towards Springs Junction. On the way we stopped to have an audioconference with students from St Andrew's College from Christchurch. Engineering Geologist Tim Sikma joined us on the phone from Westport to answer a range of questions including topics such as rock types, tectonic plate movement and the structure of the Earth. Just before the audioconference a jet plane had flown overhead leaving a vapour trail. During the audioconference the trail began to spread out and made it look like a nearby Murchison Musuem. Image: Heurisko Ltd. mountain had turned into a volcano. Just after passing through Springs Junction we came to a place called Marble Hill. Here we stopped to take a look at a wall. Why do this? Well, it is quite a special wall built in 1964 by a geologist called Frank Evison. It crosses the Alpine Fault and was put in place to monitor movement of the fault. Watch the video to learn more. We continued to head east crossing the Southern Alps via the Lewis Pass. The Southern Alps are real mountains, steep and pointy, just like the mountains a small child would draw. They This photograph in the Murchison Museum show are being worn down as fast as they are being pushed up at the the devastation of the 1929 earthquake. Image: moment. Seeing the amount of scree flowing down from them Heurisko Ltd. gives an indication of the amount of weathering and erosion happening. Our travels took us along the Hope River. This river runs along the line of the Hope Fault. This fault is an offshoot of the Alpine Fault. It runs for 230km from the Taramakau River to Kaikoura. Get a map and trace the line of this fault. In 1888 movement along a 30km section of this fault caused the North Canterbury earthquake. This magnitude 7 earthquake knocked the top off the spire of the Christchurch Cathedral. The Lyttelton Times reported: Maruia Falls. They were formed after a landslip "The spire of the Cathedral has come to grief. Its tapering, during the Murchison earthquake diverted the graceful outline, a landmark for every dweller on the plains within river's flow. Image: Heurisko Ltd. thirty miles, and a beacon for the mariner crossing Pegasus Bay, no longer cuts the sky. Twenty six feet of the upper spire have given way, and the melancholy appearance of the wreck strikes every eye." Webster, who had been a little worried about another earthquake happening any minute, was desperate for a cappucino. We promised him one after we had had finished our audioconference with students from Waitaki Girls' High School. Another set of great questions, expertly answered by Tim Sikma, who again joined us from Westport. One of the most interesting discussions was on the effect of climate change on A volcano in the Southern Alps? No, it's just a jet the height of Mount Cook. The freezing and thawing of water on trail from a high flying aircraft. Image: Heurisko Ltd. the summits of New Zealand's mountains is their major form of weathering. A warmer climate would obviously affect this so would our mountains get bigger? Our day drew to an end at the Alpine resort of Hanmer Springs but not before we made a video looking at the effects of fault movement on the region. A very big thank you to our experts from Solid Energy, geologists Wayde Dunlop, Hamish McLauchlan, Barry Walker and 2 of 3 15/06/2009 16:35 diaries/diary-4 from earthscience91. http://earthscience91.learnz.org.nz/index.php?vft=ear... Tim Sikma. Also, of course, a big thank you to all of you who came along for the ride. Today's competition clues 1. I am a town in New Zealand's South Island 2. I was the site of a large earthquake 3. This earthquake happened in 1929 The competition prize is a digital camera for your class courtesy of Solid Energy Ltd. Remember you will also need the clues from )ebster on top on Evison's Wall. It was built in Wednesday and Thursday. 1964 to monitor movement of the Alpine Fault. Image: Heurisko Ltd. See you on another trip soon. Darren (and Webster) Looking from Hanmer Springs towards the Hanmer Basin. The basin was formed by movement of the Hope Fault. Image: Heurisko Ltd. 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