A Travellerspoint blog

Day 11: Samples up!!

Time to work

sunny

I woke at 7am with a grumble, rolling to put my phone alarm on silent. Jess had the 12am-4am shift and was sleeping in the bunk below me, so I moved about the room as quietly as I could to get ready. It was more difficult than it sounded – everything I touched made some sort of noise just opening, and I was attempting to do it without turning on the light.

Eventually I managed to get dressed and ready without waking her – a monumental feat, in my opinion. I went upstairs to get breakfast, then outside to the main deck to wait with the elevator crew.

By 8am the yellow top of the elevator bobbed into view. Brett directed us to certain places to place the tag lines as the crane moved into place. I stood with an additional tag line ready.

We got the elevator on deck without a hitch. We tied it down and stowed our life jackets and hard hats. It was time to see our samples from the night.

I assisted Sean with the IGT samplers. We took them off the elevator and rinsed them down with fresh water to help avoid any unnecessary corrosion, then carried all four into the main lab to begin fluid collection. As I was the only one available (poor Niya had a 12-4am shift, and Wen yen was on shift until noon) I was immediately put to work labeling 40 vials with the sample name and number. Directly after that, I began pH and H2S.

Each IGT (Isobaric Gas Tight) sampler had a thermocouple to determine the temperature of each sampled fluid on site. They sucked up the fluid using a motor and two pistons, which we would later extract using a high pressure pump and a valve.

We did this now, one sampler at a time. By the second sampler, Jeff, Sean and I had become a well-oiled machine. Niya arrived in time for the third sampler, and Wen yen shortly after that. Niya became the ‘gas master’, in charge of the GC, and Wen yen helped Sean clean and turn around each sampler once complete.

Unfortunately, the third sampler we picked up was severely clogged with sulfides from the vent site. Fluid dripped out at an agonizingly slow pace. Frustrated, Jeff and Sean had to stop work and somehow fix the sampler so that it would yield us the samples we needed.

My job during the whole process was fairly simple, but important. We had a station set up specifically for H2S analysis and measurement of fluid pH, and somehow, through some fluke of sleep and shift, I was now in charge. Jeff handed me a lidless vial of fluid, which I placed under a calibrated electrode. It would read off a pH measurement – often between 5 and 3 – and then I had to dispose of the sample, wash out each vial including the mixing rod, and replace the electrode in the ph7 buffer. As I said, simple. However, pH is vital for Jeff and Sean, and even more so for the biologists working only a few meters away. They would often call to us asking what a certain sample was, and would grumble or exclaim to themselves and each other with each answer.

The H2S was a little more complicated. We had a setup that pumped nitrogen gas into a tube of phosphoric acid. We would add the sample to the acid, and the H2S in the fluid sample would drift into another tube, where silver nitrate waited. The H2S would bind with the silver to create silver sulfate, which precipitated out into dark flakes.

The samples for the H2S system were transferred from the sampler to my setup in syringes, which I completed with a needle and injected into the phosphoric acid. It was quite exciting, actually – instant gratification, as the H2S would bind quickly and start precipitating within a few seconds of injection.

I cleaned the needles and syringes (we didn’t have to worry so much about ‘single use’ of needles in this lab) and returned them to Jeff, who would give me a second sample and a second vial of fluid for another pH measurement. In between, he pumped out vials for NO3, NH3, SiO2, and other metals and gases to be measured. On the other side of the table, Niya manned the GC and pumped samples through to measure hydrogen, methane, and other gases.

It was a busy system, but it worked. We finished all four samplers before 5pm, just in time for dinner and to replace them on the elevator for a 6pm drop. We were interrupted, however, by news. Jason was on his way up.

It turned out that the weather was turning for the worse. Thursday evening we were to expect a storm with 40+ knot winds and swells of 10-15ft. No conditions for Jason to be in the water. Annalouise knew this and set her foot down – we would bring Jason up and be at Mariner and ready for launch the next morning.

Jason returning meant one major thing for the scientists in the lab. After a day of labor, we were to begin all over again.

We finished dinner off and re-prepped the lab for new samples. I restarted the pH meter. Wen yen cleared off her table of tools and trash to allow for IGTs to be set down. Niya and Sean recalibrated the GC. By six, Jason was on deck and we were back to work.

Four more samplers had been brought up, each full. Jeff and I took turns playing our music as loud as we dared. The mood was still upbeat, which was good. Everyone was pleased to be working after so many days of languid nothingness. By 9:30 we had everything complete. All four samplers were empty and ready to go. We had been lucky with no more clogs and fantastic samples inside.

By this time we were all exhausted. Jeff handed off his normal 12-4am shift to Rick, determined to get some sleep. Sean was out of sight as soon as we drifted away from the table. Wen yen hung about for a few minutes, then left as well.

Niya and I headed upstairs to the mess to relax and unwind for a few minutes before bed. I got a mug of water, she of sleepytime tea, and we chatted with Jess and Sunshine for a while. Eventually yawns overtook the conversation and we drifted off to our beds.

Posted by mrh616 17:31 Archived in Tonga Tagged ship dive jason revelle medea rov

Table of contents

Be the first to comment on this entry.

Comments on this blog entry are now closed to non-Travellerspoint members. You can still leave a comment if you are a member of Travellerspoint.

Enter your Travellerspoint login details below

( What's this? )

If you aren't a member of Travellerspoint yet, you can join for free.

Join Travellerspoint