The primary objective is to obtain a temporal history of across-arc variation in magma composition during five main intervals of arc evolution.
Three main hypotheses 化石掘削ゲームオンライン be tested: 1 geochemically asymmetric crust in the rear arch is either more info fundamental trait or a secondary trait that develops during backarc spreading; 2 nonsteady state events, such as rifting, play a major role in the evolution of arc crust; and 3 the origin of the Izu rear arc seamount chains is related to mantle convection patterns.
Hi, my name is Alex Nichols.
I am one of the Japan-based scientists on Expedition 350 that are using the drill ship JOIDES Resolution to drill into the seafloor to understand more about the volcanism in the Izu Island Chain.
JOIDES Resolution in Keelung.
The science team on the expedition is international.
As well as the 6 scientists based in Japan, the team includes 11 based in the USA, 4 in UK, 2 in Germany, 2 in Sweden, 2 in Brazil, 1 in France 1 in Norway, 1 in Mexico, 1 in Australia and 1 in China; 32 scientists in total.
We have a range of jobs to try and get as much information as we can onboard the ship from the rocks we recover as we drill and measurements that are made with special tools in the hole after we have finished drilling.
My job, along with 12 other scientists, is to describe the rocks in the core that are brought back up through the drill pipe and on to the ship.
There are also 2 people onboard whose job is to publicize the expedition and arrange ship-to-shore events with schools, museums and other institutions.
Several Japanese schools and universities have had virtual tours of the ship.
There is also an international crew and team of technicians who keep everything working smoothly for us, from equipment in our laboratories to doing our laundry.
In the first four weeks we drilled two holes.
The first east of Aogashima Island to examine the properties of the rocks in this area in order to determine how suitable this area would be for a future ultra-deep drilling expedition.
Then we moved to our key site to the south-west, west of Myojin-sho, and began drilling a hole with the target to reach rocks about 35 million 化石掘削ゲームオンライン old at depths of 2000 meters below sea floor.
Firstly we you ハリファックスncのカジノ necessary drilling 化石掘削ゲームオンライン soft muddy sediments.
When the mud became too hard at about 450 meters below the sea floor, and became a rock, called a mudstone, we stopped drilling that hole and pulled up the drill pipe and moved a little bit, just 10 meters or so and quickly drilled a new hole with a more heavy duty drill bit, called go here rotary core barrel.
Once we reached the same depth as in the first hole we started collecting the core again, more mudstone.
We continued drilling to 1100 meters below the sea floor recovering cores containing a mixture of mudstone and layers of volcanic ash that had hardened and become rocks when they are known as tuff.
These ash layers have come from old volcanoes.
Perhaps close by, perhaps further away on the Japanese mainland; it will be our task after the expedition when we return to our home institutes to work together to try and find this out.
At 1100 meters the decision was made that if we wanted to drill deeper we should prepare a cased hole.
First, source, we replaced the drill bit on the end of the drill string with special tools to measure 化石掘削ゲームオンライン physical properties of the rocks in the walls of the hole.
This can help us say more about the rocks we drilled through than just direct measurements and observations on the rocks, particularly in areas where not all we drilled through was recovered.
Derrick while they are bringing up the drill string and putting it away on the ship.
After we finished logging the hole we moved another 10 meters or so and started drilling a third hole and began to case it.
Casing the hole refers to lowering a metal pipe into the drill hole and securing the bottom with cement.
We cased to 1089 meters below the seafloor the deepest this ship, the JOIDES Resolution, has ever cased.
The Chikyu, another drill ship used for scientific research, has cased deeper holes.
Casing makes the hole a lot more stable and protects it from collapsing.
This increases the chances of the hole surviving as we drill deeper, preventing the upper 1000 meters of rock we have drilled through from collapsing in on the hole and stopping us from reaching the deep, older rocks that we are really interested in recovering.
Casing is a complicated procedure and casing such a deep hole takes time and we had to be patient.
The new rocks have been more and more interesting this week and hopefully the hole is stable enough now that we can just keep drilling until we run out of time and have to pack up and head home to Yokohama.
Rocks recovered by drilling, scientists mark with stickers where they want sample taken.
The science team works 24 hours a day, divided into two groups that each work a 12-hour shift, so all the work can get done.
But it is not all work; when you are not working you can use the gym like Jihui-san, watch movies, play games or just sit out on deck and get some fresh air.
Sometimes there are birthday parties, and now and again on special occasions, parties.
Every week, if the weather is good, there is a BBQ out on deck, and you can carefully construct towering beef burgers with all the salad and meat available.
While outside, if you are lucky, you can see wildlife; several birds have used the ship to rest and an increasing number of ペンギンダイナー4ゲームオンライン think we are an island.
Fluorescing jellyfish, squid, huge schools of tuna, flying fish, turtles, sharks and an albatross have been spotted.
And even if there is no wildlife, on clear days there 化石掘削ゲームオンライン always the sunrise and sunset depending on which shift you are working.
For that purpose, alternating field demagnetization on archive halves is performed with a cryogenic magnetometer.
This cores study is combined with the analysis of discrete samples cubes taken on working halves.
Different magnetic measurements are performed on cubes in order to better determine the primary magnetization and the magnetic mineralogy.
This was my main activity during this week.
On Saturday, April, 26, a re-entry cone was lowered down to the sea floor for casing operations in a new hole.
These operations are needed to drill deeper in order to recover the basement.
Because of that, scientists have plenty of time to write reports and to enjoy life on board by organizing special events.
On Friday, April, 25, it was the ANZAC Day, a national day of remembrance in Australia and New Zealand.
To commemorate the day, Bob, the Australian paleomagnetist, has suggested playing a traditional ANZAC Day past-time called Two-Up.
Day ナンバービンゴインタラクティブゲーム night shifts scientists met on the helideck after lunch to play for 15 minutes.
Two coins are thrown into the air by a spinner.
Depending on the result, the spinner or the click win the bet.
It was a great time outside on a rare sunny day we had since the 化石掘削ゲームオンライン of the cruise.
A カジノフィエスタミラフローレス新年 birthday parties will come soon.
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