Main contents

1、新着論文 2、論文概説 3、コラム 4、本のレビュー 5、雑記(PC・研究関連)
6、気になった一文集(日本語English) 7、日記(日本語English


End of X

We finally decided to finish coring operations in the last site, CAPE.
All laboratory are ready to be closed after cleaning up and returning the things as they were.

Shipboard scientist must keep in shift, until 6:00h on 31 March, and we will leave the JR at 9:00h.
We will go to the hotel together by bus, and that is the end of all activities of the ex[edition.
After that, we are free!

I'm planing to enjoy sight-seeing in the Cape Town, but first of all, I need good beer!

It will be a long day, because I must keep awake for about 20 hours until I go to bed in the hotel.
We have the right to enjoy the party, because 2 month long cruise will finally end.

This is the last diary that I write in English (and from the JR).
I will post a blog about my first experience of IODP cruise, after I come back to Japan, will will be written in Japanese. I hope it will help young scientists who have interests in joining the IODP expedition in the future.


Sampling plan

We  are now in the proximity of the last coring site, CAPE. It is located in the continental shelf offshore of the Cape Town Port.
We stay the last site for a couple of days and get off the ship on 31 Mar 10:00h.

We have finished writing summary of previous three sites and presentations (MZC, ZAM, and LIM).
An introduction of how to sample the sediment core was explained by core curator and we must fill in a special forms before the arrival at Cape Town.
Our sediment cores will be transported to Texas Univ. and later we gather there again for the sampling party, which is planned be held at the end of September this year.
We will stay Texas Core Repository for one week (perhaps), and allocate the sediment according to everyone's request (e.g., 10 cc sample from the top 3cm in Site1474, Working half, Hole A, Core 3, Section 1).

I guess that some of the cores obtained at the last site will be stored without split and being described. The first core on deck will be 6 hours later from now.
It takes several hours to make sediment core at room temperature, so the first core will be described by daytime shifters (I'm in a night shift).

It was long, long two months. I want to take a rest for a while but I must attend at an international meeting held at Hongo Campus (Isoecol) after just "one-day" off.
My Brazilian and French friends said that they will take a vacation after the expedition for 1 month and 1 week, respectively. I realized that cultures and employing systems are completely different among countries.

But, anyway, good beer and wine are waiting for me on land!


Sand and foram

We finished drilling 5th site, Limpopo River.
The sediment was accumulated in a moderate rate and we could reach to Late Miocene.
The sediment contain amazing number of foraminifers. It will be a great paleoceanographic record that we will make during the post-cruise phase.

However, Sedimentation pattern of this site is quite complex, so we concern about sediment drift. Chronology will be the most important issue when we discuss the isotopic and paleontological records obtained from this core.

Now we are heading for the last drilling site, Cape Town. But we have not yet finished describing the sediment from Limpopo as well as that from Mozambique Chanel sediment.
At the same time, we have to think about our post-cruise research and discuss with a lot of people about sampling strategy or potential collaboration.


Great Zambezi River

We arrived at 4th drilling site, near the mouth of Zambezi River.

The water depth is only 400 m, so the coring process is so fast! We obtain a new core every 15 minutes! We arrived here yesterday but have already drilled two holes.
We are describing cores while writing the site report of the previous site.

Sedimentation rate of this site is amazingly high, which is about 1 meter per thousand years (1 m/ka). It is about 30 times faster than the pelagic site (2,000 m water depth).
Main composition of the sediment is quartz and clay minerals transported by Zambezi River. We can also see some remains of plants (e.g., fragments of trees and leaves).

I have never seen riverine sediment cores, thus I enjoy seeing a lot variety of minerals originated from the continent (e.g., zircon and hornblende)
More than 95% pf sediment is consist of terrigenous materials and biogenic ones such as foraminifera, coccolithophore, and diatoms are very rare.

I miss forams so much...

Soon after we finish drilling the 3rd hole, we will leave for the next drilling site, Limpopo River. It takes only 2 days from here to the next site, thus we again will be busy preparing for presentation and writing the site summary.


Mozambique Chanel

We arrived at the 3rd drilling site, Mozambique Chanel.

This area was before drilled under the DSDP cruise (Site 252) and the drilled core is archived in Kochi Core Center.
We expect that we can obtain well-preserved pelagic sediments covering Plio-Pleistocene. Sedimentation is not so high that we will easily get to Pliocene/Miocene boundary.

The sea is covered with a lot of eddies due to complex ocean current systems and characteristic geography, but wave is somewhat calm. I can feel almost no movement of the ship.

After the arrival of the first core, we will spend very busy three weeks until the port call.
We will have to describe sediment cores while preparing for site summary, and then transit to the next site.

I hope I can see a lot of planktonic foraminifers in the sediments that will be used for isotopic measurements during post-cruise moratorium period.

ETA of the first core is when I'm dreaming in the bed today.


Heading north

We are now heading north, the northernmost site of our cruise, Mozambique Channel.

We nearly gave up the drilling at the site, but finally we obtained the permission of drilling!

We are now preparing for reports of previous site, Agluhas Plateau. It still have additional four days until we get to the Mozambique Chanel, so we enjoy the subtropical weather in outdoor bench.

A beautiful sunrise (I have not seen the sunset for one month)

A relax time in picnic table

After the arrival to Mozambique Chanel, we will drill additional three site. Thus, it will be deadly busy in the coming three weeks!

As the remained drilling sites are generally shallow (< 1,000 m), we will get sediment cores one after another.


End of Hole (APT Site)

We drilled 6 holes at APT Site, Agluhas Plateau, and at last left the site.
The weather was fine for the first couple of days but tuned bad later. The weather affected the quality of sediment cores, because ship movements sometimes destroy cores that is ready to be drilled.

Unfortunately, we could not obtain the complete splice core at this site, but could obtain plenty of sediment that is well-preserved.

Foraminifers' shells, of which I have the greatest interest, are abundant in the sediment. Moreover, I enjoyed seeing a lot of diatoms, radiolaria, and variety of minerals in smear slides.
Agulhas Plateau is a sensitive region to past environmental changes, because degree of Agulhas Leakage changed periodically in glacial - interglacial climate changes.
After the expedition I will pick up the forams and measure trace element and isotopes of them. The other day I gave a help to micro-paleontological group, and realized washing, sieving, and picking processes are so hard!

Today is a leap day as well as a half way of the expedition! Thus we call the day as "lump day (leap + hump)". A midnight dance party are now being held. Everyone is dancing in the loud music.

The next coring site has not been decided yet (hopefully, ZAM site), but we are heading north.