The calm before the storm?……Nope!!

The “Pre-OSP” at the MARUM – Center for Marine Environmental Sciences, University of Bremen, Germany, does not only include measuring Thermal Conductivity (TC) of the full cores from IODP Expedition 381 by the European Petrophysics Consortium (EPC) Team (see https://esoexp381corinthactiveriftdevelopment.wordpress.com/2018/01/19/dancing-in-the-reefer/), but is a very busy preparation phase for the Expedition´s Onshore Science Party (OSP).

The preparations at MARUM (http://www.marum.de/en/Research/Partner-to-the-ECORD-Science-Operator.html) started many months ago, when for example we reserved the accommodation for the Science Party, this at a stage when we did not know the exact timing/duration of the OSP or the exact amount of recovered core! We also reserved numerous lab and office spaces ahead of time, as well as measurement slots in a variety of MARUM laboratories (e.g., core sampling, core logging and scanning, geochemistry, geotechnics, mineralogy (XRD), palynology, paleomagnetics, petrophysics), to ensure that sufficient capacity will be available for the OSP for the IODP-MSP standard measurements.

Right after the end of the offshore phase on Dec 18, the expedition data were made available for the Science Party on a MARUM server. This was key, meaning that all science party members could immediately access the information required to revise their preliminary sample requests, which were initially submitted before the offshore phase. The beginning of the New Year was quite exciting as the expedition cores arrived at MARUM on January 3! The two refrigerated containers were unloaded instantly and Alex and Holger safely transported the 21 core boxes, into the reefer of the IODP Bremen Core Repository (BCR) in what seemed to be no time.

Since the Autumn we intensified our preparations, preparing the OSP workstations in a variety of labs, setting up IT hardware in numerous offices and labs, loading the latest curation database version on the computers, testing equipment, checking our stocks of consumables, discussing how to optimise core-flow plans and when and how to integrate outreach activities. Equally important is to arrange procedures and reservations with the Mensa, where everybody has lunch from Monday to Friday! Combined with grocery shopping for coffee breaks and snacks and catering for the weekend meals, it is quite a complex and intense logistical exercise! Nevertheless, we are still working regular hours (ok, some of the time) and not in shifts yet. This will change for all of us later this week!

Successively, during the month of January the sample requests were shared with the Co-Chief scientists Lisa and Donna as well as the EPMs Gareth and Jez. Together with Ursula they form the so-called Sample Allocation Committee (SAC). The SAC establishes a project-specific sampling strategy and makes decisions on project-specific sample requests received before the drilling project, during the drilling project including the OSP, and during the moratorium period, that is twelve months after the end of the OSP.

In these last few days before the start of the OSP the setup of some of the work stations are still to be finalised, but all of us are very excited to finally start splitting and processing the new cores and looking forward to finally meeting the whole Science Party.

Last but not least we are looking forward to continue working and collaborating with the wider ESO team, which comprises colleagues from the BGS, the EPC, and us at MARUM. All of those involved in the OSP – scientists, ESO staff (including the twelve University of Bremen Geosciences student helpers) – comprise a team of more than 70 people, who will closely work on processing and describing the 1645 meters of cores and samples in two shifts over the course of a full month!

Ursula Roehl.

Image captions: Beakers all ready for the moisture and density (MAD) analysis on Expedition 381 samples; Ongoing preparations in the core description lab; The core splitter nice and shiny, but still asleep; Earlier stage of microscopes set up in the core description lab; Petrophysics equipment awaiting installation; Patrizia unpacking and assembling microscope equipment; The calm before the storm, scientists’ office not claimed yet  (All images U.Röhl, ECORD/IODP)

core

Exp. 381 core boxes on arrival at MARUM (U.Prange, ECORD/IODP)

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Dancing in the reefer

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Unloaded core sections in thre reefer, waiting to be measured and then put back to boxes. Photo: N. Denchik, ECORD/IODP

The almost a month-long “Pre-OSP” phase started on the 3rd of January 2018 at the MARUM institute in Bremen. The Pre-OSP this time focuses on measuring Thermal Conductivity (TC) of the cores from IODP Expedition 381 – the last measurements that require the cores to be whole – and preparation for the OSP (Onshore Science Party) in February when they will be split.

We, the “TC measuring” team (Laurence, Nataliya, Malgorzata) and Sally (EPC coordinator) arrived at the MARUM – Center for Marine Environmental Sciences in the morning of the 3rd of January, after leaving home on the 2nd – almost right after New Year celebrations! The beginning of the New Year was an exciting one as we were busy preparing our workspace for measurements in the four degrees celsius reefer, testing equipment and finalising plans.

As always, we were warmly welcomed by the MARUM staff, and we spent some time with them chatting over good coffee and cookies during breaks. These two days (2nd and 3rd of January) seem now like a relaxing warm-up before the work on continuous measurements in the following weeks, and the excellent evening dinners we had (traditional German food) seem like an unreal dream because…

…in order to complete TC measurements on the huge number of recovered cores from IODP Expedition 381 Corinth Active Rift Development, measurements are undertaken round the clock… in twelve hour shifts.

Laurence is on shift during the daytime (5 AM to 5 PM), and Nataliya together with Malgorzata work at night (5 PM to 5 AM).

TC measurements are recorded using the full space line source, the VLQ or “needle probe”, inserted into the cores along the same plane that they will be split. Before starting measurements the equipment was checked for calibration and then checked again using dummy cores: one made up of saturated and compacted topsoil and another of water-saturated clean sand. Both very different in terms of TC response…

Cores from IODP Expedition 381 that have been measured thus far have been full of surprises. Results have kept us on our toes in terms of gathering high quality data, and served to heighten our anticipation for finally splitting the cores in February and getting to see with our own eyes what is inside.

One thing that we have learned over the past couple of weeks: the better results – the better mood of the Pre-OSP team members! When we obtained the first measurement with a solid data-set, we started to dance in the reefer! Which is by the way a very good way of keeping yourself warm. That’s it – dancing, some yoga, jumping and jogging around the reefer’s shelfs are the top activities we do to keep ourselves warm during the long periods of time that we have to spend in four degrees Celsius. Though, unloading or re-loading core sections out of and into the transport boxes is a bit more physically engaging way of keeping the circulation flowing. Laurence once counted how many core sections he moved from and out the boxes during one shift and the number exceeds 300! It’s definitely good exercise. We will have some more muscles after Pre-OSP, that is for sure!

We celebrated Laurence’s Birthday on the 15th of January, at 5 am in the reefer in four degrees Celsius. Not everyone gets Birthday wishes at 5 am!

We do not have time to explore Bremen at this time. Twelve hour shifts leave time only for TC measurements and some sleep. Not a lot of sleep by the way, but the results of TC measurements are their own reward!

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Great start for Laurence’s birthday morning. Photo: N. Denchik, ECORD/IODP

 

Staying on the Spot

Chief officer Sebastian and the DP consoleby Evert van den Berg (2nd Officer, DPO)

To be able to drill in the seabed hundreds of meters below the sea surface Fugro Synergy needs to stay in the same position on the surface, sometimes for weeks at a time. As anchors would be impractical in the water depths we work in Fugro Synergy is equipped with a Dynamic Positioning system (DP for short), meaning she is kept in position using her propellers.

The DP system receives input from a number of sensors (DGPS and hydro-acoustic beacons for position, gyro compasses for heading and several wind meters) and then continuously calculates the trust settings (both force and direction) required on the propellers to generate the exact forces needed to counter the outside forces and stay in position. In the generally quiet waters of the Gulf of Corinth we are often able to keep the ship within about 20cm of the set position, though we may move over a meter in the strong squalls that sometimes blow through the Rion strait. On one occasion we recorded a 75kn (140km/u) gust while holding position on the DP.

JEverest@ECORD_IODP_20171202_032824

An interesting piece of history: While DP systems are quite common today in the offshore oil/ gas and wind energy sectors as well as on cruise ships, the first predecessor of the technology was actually developed for a ship used by an early predecessor of the IODP. They used converted barge called the CUSS1 during project Mohole in 1961 that attempted to drill through the earth’s crust where it was thinnest: on the bottom of the ocean. As the water depths were much too deep for anchors the barge was kept over the borehole using 4 thrusters operated manually in combination with a crude sonar system to indicate the position which kept them within around 180m of the site, just enough not to bend the pipe too much. 60 years of improvement in computers, positioning systems, electric drive converters and ship design have helped a lot in making our jobs easier!

2nd officer Vlad controlling the ship on DP

The DP system is controlled from the bridge, and while the computer is doing the hard work of constantly correcting the settings of the propellers it is monitored by the one of the duty Dynamic Positioning Operators (DPO). The DPO has to make sure that all parameters stay within limits and also anticipate changes in the weather and other operating conditions. In case of failures the DPO can switch between the multiple systems that provide redundancy, or can take over manually as required; different control modes are available in case of failures from fully automatic, via joystick to control to full manual. As on most ships the DPOs are also the officers in charge of the navigation of the vessel and our normal DP watches consist of a senior and a junior deck officer who are on the bridge together, taking one hour turns at the DP system controls. The chief officer and first officers are changing shifts at midnight and mid-day, while the two 2nd officers are changing at 0600 and 1800 to make sure there is enough overlap between shifts.

Also on the bridge is the survey station, here the surveyor determines the exact position of the borehole. First the position of the ship is fixed using GNSS receivers that can use signals from both GPS and GLONASS satellites which are then corrected using Fugro’s Starfix system to an accuracy of <10cm. The exact position of the Seabed Frame (and drill pipe leading through it) is then fixed using the USBL (ultra-short baseline) hydro-acoustic systems integrated in Synergy’s hull and a transponder mounted on the frame.

Surveyor Golden working on fixing the postion

Hidden Depths

Our drillers and ADs are multi talented. Having the ESO team on board the Fugro Synergy has moved some of our drilling team to commit their experiences to verse. We thought these were awesome! Thanks to Sean, Adam and Dan!

 

Driller’s Poem

Zero to Hero in 5 easy meters,

Running around deck I’ve heard that Dan’s feet hurt.

Turning and churning were stuffing her in,

Over my shoulders the eyes are watching.

All going smooth, all happy all well,

Oh s#*t there’s sand. Good sample- farewell!!

Pulling it back, a bit nervous and twitchy,

Graham beside me his feet seem quite itchy.

Barrel on deck, here comes Dave with a frown,

Always concerned that our rates will come down.

Cheer up my handsome the bleddy things full,

I can’t believe you were worried at all.

Sean Baxter

Nightshift Driller

 

Rooster Box Poem

Up in the Rooster Box

Looking down from above

Waiting for the tool

To show its face from the mud

Me and my Filipino friend

Try and keep spirits high

As the driller sends us up high into the sky

Chilly today around 30 knots

But the view isn’t lost upon the oceans we cross

Shift’s almost over, time for some lunch

Chicken and chips

Yep…..every day of the month

Quick gym sesh

Then off to count 40 sheep

Sandwich Dan’s turn tomorrow

Time to sleep now…peace

ADs No.1.5 (Adam) and No. 1 (Dan)

Nightshift

The Drillers’ View

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The ADs describe their working day

A typical day for the Day Shift will start with a Toolbox Meeting in the Conference Room at 11:30am.

After the Toolbox we will make our way to the Doghouse for a Handover from the Night shift. This will consist of the drillers having a separate Handover in regards to the hole and how it’s drilling.

The ADs (Assistant Drillers) will handover if there’s any Equipment Isolations or Permits to Work open and if so describe the nature of the work. The Night Shift will also inform us of any maintenance they have performed on equipment or breakdowns they have encountered.

So during drilling operations the ADs will carry out maintenance, mix mud and generally help out anyone requiring assistance in between core runs.

Our main areas of responsibility are to mix mud, operate the PDPH (Pipedeck Pipehandler) and TFM (Tubular Feeding Machine) and Tool Handling when recovering core samples.

Mixing Mud

DSmith@ECORD_IODP (143)

 

Using the sophisticated mud system on board we, at request of the driller, have various viscosity muds readily available depending on the ground the driller is coring through. This product clears waste material, called “cuttings” away, or is used to stabilize the hole.

“Mud” is a mixture of fresh water and a clay product called Bentonite or other additives depending on the type of drilling in progress. It is mixed with fresh water to increase dispersion into any unstable layers. We can also change the viscosity. So a thicker mud is used for sand layers where the ground is less stable where a thinner mix would simply disperse into the ground providing no support. We measure the viscosity using a beaker and funnel, timing how long it takes to reach a certain level.

Current situation

We are drilling through clay layers and the hole is stable so sea water is being pumped down the “String” to clear the cuttings away. The drill pipe in the hole is referred to as the “String”.

So far maintenance-wise the ADs have checked that the mud pumps are running smoothly and the mud stored in the tanks is agitated so as the product does not separate.

We will be performing a Derrick sweep later in the day to make sure systems housed within are all functioning. This consists of greasing sheaves, physically checking fixings and secondary retentions and checking for corrosion to the structure. Also a good time to take in the stunning views of the Gulf.

We now await the arrival of a fresh core sample to be winched up where we will strip the core barrel, extract the sample and rebuild the barrel to send back for another core run.

Why are we here? Plate tectonics and the Gulf of Corinth

You may have wondered why we are drilling and sampling the sediments in this beautiful part of central Greece. The Gulf of Corinth is part of a continental rift system – where a tectonic plate is pulled apart and stretched. This is the first stage in the process that ultimately forms our oceans and ocean basins, such as the Atlantic Ocean, and has shaped the Earth’s surface that we know today. The rifting process causes the Earth’s crust and lithosphere to stretch and thin and the surface to subside. In the upper part of the crust the stretching and subsidence is taken up by fault structures which move during earthquakes every few hundred years. This creates a hole or basin which fills with sediments and water. In the Gulf we have up to 2.5 km of sediment and nearly 1 km of water. The Corinth Rift is only in the very first stage of rifting – where we are drilling, rifting only started about 1 or 2 million years ago. That may seem long for the non-geologist but is a fraction of the time it takes to form an ocean basin.

Cartoon

The reason we are working in this part of Greece is to understand the first stage of this process which is very well preserved here, particularly in the deep sea sediments of the Gulf of Corinth. By sampling the sediments we can determine their age, and from that we can tell how fast the faults slip, and when and how fast the basin opened and subsided. Knowing how fast the faults are moving will also help us understand better their earthquake-generating potential in this very seismically active region. We can also see how basin formation and the climate of the area caused sediments to be eroded and transported into the basin.

If you are interested in learning how the environment of the basin changed, please also take a look at the post from Clint Miller on “Sea Level Change” which tells you about how the basin has been affected by sea level change and tectonics. Also take a look at the post from Rob Gawthorpe “Onshore from the Offshore Perspective” to see how the rift faults have affected the shores of the Gulf of Corinth.

Lisa McNeill

Images:

View east along the southern shore of the Gulf of Corinth, near Aigion, showing the topographic effects of the rift faulting. The hills to the right are uplifted whilst the Gulf to the left subsides.

Cartoon showing how the Earth’s lithosphere (the tectonic plate) and the crust thin during stretching. The upper crustal stretching is generated by movement on faults. The fault movement and crustal thinning cause subsidence which create the water and sediment filled basin of the Gulf of Corinth.

Sea level change – signs in the sediments

How does sea level change affect marine life? This is one intriguing question Expedition 381 is exploring. We know sea level rises and falls around 120 meters (~400 feet) every time the planet alternates between glacial and interglacial periods. Scientists use the term glacial to describe intervals when the Northern Hemisphere had large ice sheets extending well into Canada, United States, and much of Europe. As ice built up it took water from the ocean lowering the average sea level of the planet. The Gulf of Corinth is an ideal location to study the rise and fall of sea level because the entrance (Rion sill) is only 61 meters below sea level. Therefore, the Gulf of Corinth was sometimes connected to the Mediterranean and at other times it was an isolated lake!

Of course, seawater and lakes have very different animals and plants. Also, oceans have distinctive chemistry compared to freshwater. These differences will cause changes in the geology which we can observe in the drilled cores. Many of the records we are collecting show these variations clearly! As we drill in different locations and measure different aspects of the sediment and pore water, we learn the fine details of these processes.

As all fun science however, the more we learn the more questions we create!

Clint Miller

Main image: Simone Sauer and Patrizia Geprägs collecting methane samples. Courtesy of DSmith@ECORD/IODP