Fossil Coral Mountains

By Liz Wiggins, Undergraduate Research Assistant Extraordinaire

With our time on the island quickly coming to an end, we were down to the daunting final task of taking inventory of all the fossil corals we collected. By this point there were mountainous piles of coral that had slowly accumulated at our temporary home, Dive Kiribati. We decided to sort the corals depending on how pristine they looked and took data on the species collected, length of the growth axis, and condition of the piece. All together we ended up with a respectable grand total of 671 fossil corals. Although most will be stored here on the island for now, the best of the best will be taken home for U/Th dating and analysis.

As part of my summer project as an undergraduate student, I will be investigating how dissolution affects the geochemistry and morphology of corals. While we were completing the inventory, if any piece looked particularly altered it went into a special “Wiggins” pile that was reserved for small and pitiful corals. Any piece that made my fellow paleoclimatologists cringe only added to my excitement! I chose 10 fossil corals that represented a gradient of diagenesis ranging from a nearly unaltered sample to a calcite ridden and visibly dissolved poor excuse of a fossil coral.

These “special” Wiggins corals will come home with us to Atlanta where they will undergo geochemical analysis and later be placed in a device that simulates rain falling on the coral for a certain length of time. Dubbed the “Rain Machine” this instrument is a self-filling reservoir that slowly drips water onto a piece of coral at a constant rate, basically creating artificial rainfall.  Afterwards, they will be reanalyzed to see exactly how the geochemistry and morphology changed. This has important implications for paleoclimate reconstructions using fossil corals as climate proxies, because nearly all of the corals in question will have been dissolved in some way. Although the effects of some types of diagenesis such as forming calcite or secondary aragonite have been thoroughly tested, how dissolution alters the coral is not well understood. Christmas Island has awarded me with excellent, horrible fossil corals that fit perfectly for the job.

To relieve our boredom during the long days of cataloging, our breaks consisted of visiting some of the local shops for souvenirs to bring home for our friends and family. This island very obviously doesn’t have many tourists, as most of the stores were laden with canned goods and necessities for island life with very little in the way of souvenirs. During one of our many stops we parked at a small community that swarmed with small native children. They excitedly ran up to the truck and began rubbing and even kissing (poor Diane) our comparatively pale arms while happily chanting “white skin” in Gilbertese, the local language. Following the truck all the way to the road, they cheerfully waved and yelled good-bye until we were out of sight. But all hope was not lost, our local caretaker, Anami, led us to some interesting native vendors that had very unique souvenirs to take back with us, complete with jewelry and tasty treats all made on Kiritimati.

Sadly, this is our last night of the expedition and all the final packing is nearing completion. Tomorrow we will be sure to include one more post during our extended layover in Hawaii, complete with a blurb from each of the remaining members of our team. 

Enjoying the high life on Christmas Island: a haircut and clubbing

by Diane Thompson (U. Arizona)

Our next goal was to finish drilling the large fossil coral heads we had found strewn across town.  On our last drilling escapade around town, we had discovered just how tiring and inefficient the hand water pump for the drill was.  But flushing the drill hole out with water as we proceeded was particularly essential for drilling the old fossil material on land.  Hussein and Liz devised a clever way around this problem using an extra one of Jess’s large funnels and good old gravity (see photo).  Worked like a charm and saved us a lot of time and energy. 

Now that we could drill more efficiently at our home base, where we have an unlimited supply of water from the lagoon, Liz and I set off to collect the large fossil corals from around town.  Preparing for my first attempt at driving stick, I decided it would be a good idea to bring the radio.  Apparently Anami thought something was fishy, and asked me if I was ok to drive.  I guess she caught on to the slight hesitation in my voice, because she took me for a test drive around the “block”.  Guess I passed, despite initial difficulty with the terrible power steering (there may have been a moment where I was headed for a tree).  Anami sent us on our way with the radio and a reminder to “stay left!”

I was actually very pleasantly surprised at how smoothly the driving went, even in old rusty, and we made it around town with no issues.  And Liz and I were able to muscle the large, heavy colonies into the truck.  But it took longer than expected because we passed some of the corals we were looking for and went too far. I’m not surprised since it took nearly all the concentration I had just to change gears, drive on the wrong side, watch for the many speed bumps, and avoid random people and animals in the road! 

By the time we got back, Jess and Hussein had installed one of Jess’s loggers on the weather station and we drilled like crazy for the rest of the day, getting 20 cores from fossil corals!  Of course, not all of them were great, as some fossil corals are too degraded to get a good core out of.

After showing Hussein the ropes, I handed the drill over to him for the last core.  My back was killing me from leaning over all day, so I was very thankful for his eagerness to learn.  I returned to the job of helping to brace the core barrel until it was making a groove in the surface.  But as Hussein started drilling, somehow my hair got wrapped up in the drill!  Luckily Hussein stopped quick enough that it wasn’t pulled from my scalp, but it was still quite uncomfortable.  How the heck did that happen—I’ve done this countless times with no problem?  I blame the trade winds (we were out drilling on the jetty) and my terrible wispy hairs that stick out of my head in humid weather (aka my “wings”).  Liz quickly fetched the scissors and amputated one of my wings, freeing me from the drill.

After my new haircut, we decided it was best to call it a day!  At dinner Anami told us that she was going to bring us clubbing tonight, but we all thought she was joking and referring to the club right here at Dive Kiribati (i.e., Hussein playing music off his phone and using his flashlight as a strobe).  But no, she brought us to THE exclusive club on Christmas Island.

We arrived to find the club virtually empty, with only two people dancing.  Yet within seconds of arriving, I felt someone tapping on my shoulder and realized I was already being asked to dance.  Thankfully, unlike clubs in the states, dancing is actually modest here.  Well, at least until he got in my personal space to tell me the history of Christmas Island.  I couldn’t understand a word except “Christmas”.  I need another drink... 

We headed back to the parking lot to mix up some rum and cokes (yup, drinking in the parking lot—classy!).  A pig came to join us, but was quickly chased of by Liz (I guess running after pigs classifies as entertainment in South Georgia?).  We went in to brave the club scene a couple more times, but spent much of the night in the parking lot enjoying the rum and the incredible stars.  Being this close to the equator you get to see the constellations of both hemispheres, so the star gazing is incredible (not to mention minimal light pollution!).  Another productive day and fun night on the island!

Angry Birds: Christmas Island Edition

by Jess Conroy

Hard at work labeling samples in the field.

The plan was simple: Rent a mighty truck, drive to the remote south side of the island, and do some scouting and collecting of fossil coral material. And camp overnight on the beach. Fun! However, our execution of this plan was far from perfect. Luckily for y'all, our adventures should be entertaining to read about.

We had previously rented a truck from a man living near the Captain Cook Hotel. He didn’t take a liking to us after our first rental, perhaps because we ran over his volleyball net. But, he agreed to rent us the truck for our camping expedition, at the price of $70 a day.  He dropped off the truck for us on Thursday as promised, but parked a good quarter mile away from Dive Kiribati, so while he snoozed in his truck, we were clueless about the location of our vehicle and the feasibility of the day’s plans. But, being eager young field hands, we drilled a large Porites coral in the yard of Dive Kiribati while we were waiting. Thankfully Anami spotted our truck while out on an errand, and we finally loaded up our gear and set off around 11:30 AM. So much for an early start. And then came the first obstacle: none of us had ever applied our immense brains to the task of driving stick shift. So, with some trepidation, I climbed into the driver’s seat of the Aussie-made truck. And I did it!  I drove through town, braving speed bumps and shifting gears, on what for me seemed like the wrong side of the car on the wrong side of the road. I owe many thanks to Anami for teaching me, and also for taking over when the roads got brutal.

Our route to the south side was based on a red dotted line on a tattered map Diane was smart enough to bring along. Our first attempt at finding this road led us to some amazingly old-looking Porites corals lining a lagoon laden with red gelatinous bacterial mats. Since we were pretty far inland, the presence of these corals implies a higher sea level at some time in the past. Perhaps the Last Interglacial? We excitedly geeked out over our discovery.

Hussein hauling a fine specimen to the truck.

Shortly afterward, we came to our first road closed sign of the trip (many areas of the island are often closed for environmental reasons, like seabird nesting). We turned around, headed out to the main road, and found the only other road cutting across the island. We turned onto it, into the wilderness of Christmas Island. The road was exceedingly narrow, and mangroves and other shrubs were beginning to reclaim their territory. As the truck forged ahead, those of us sitting in the back were whacked repeatedly, and a constant, painful screeching sound made us wonder how irritated the truck owner would be when we returned his vehicle covered in scratches.

We finally emerged, and made the executive decision to take the long route along the edge of the island back to civilization. This road appeared nicer on the map, but would add about 2 hours or more to our journey. But now it was coral time. We started combing the rubble fields, taking a water sample here and there. We found plenty of samples, but the material seemed much more weathered and beaten down, hinting the fossils were much older than the assemblages on the other side of the island.

Diane in her mosquito net. Note ominous rain clouds in background.

Toward the end of the day our truck became infested with some sort of mangrove-dwelling insect. It was getting creepy, so we grabbed our gear and set up camp on an empty expanse of beach. Diane and Anami were eager to sleep outside, so Hussein claimed one tent and Liz and I set up in another, while Diane and Anami rigged mosquito nets. We then dug through our cooler to find dinner, finding a cornucopia of processed meat products to indulge on—hot dogs, vienna sausages, and spam. Liz was incredibly fond of the ‘vienner sausages’, but I’ve decided they should be reserved for the apocalypse. Later in the evening as we sat around the fire, Liz and Hussein taught Anami such great American traditionals as ‘Milk Shake,’ ‘Love Games,’ and ‘Get Low.’

We enjoyed a great fire prior to the deluge.

We were keeping our fingers crossed that the skies would remain clear, but it was not to be. As soon as we got comfortable, the rain came. Diane and Anami booked it for the truck, and poor Hussein shivered in the fetal position in his leaking tent through the night of storms. We were a sorry sight in the morning, but we got down to business, collecting samples from three more sites as we moved up the beachside road toward home.

Or so we thought. After driving about an hour or so on the only road traversing the south side, we came upon a terrible sight: a road closed sign. We debated our options: ignore the sign, and keep going, or turn around, and attempt the bushwhacking road again.

One should always obey road signs on Christmas Island.

We ignored the sign. About five minutes down the road, we began to realize why the sign was there. The sky became black with seabirds. They seemed angry. And then the truck stopped. Hussein climbed out, and with a look of terror, said “There are birds sitting in the road.” I peered over the side of the truck. The road was dense with birds. Now we were down to one option. We backed up and booked it in the other direction. I got a sinking feeling in my stomach, thinking we would soon be too low on gas to get home.

Birds. Lots of birds.

But thankfully, we made it home with all our rocks. And we were able to buff out most of the scratches on the truck. Disaster averted.

Don't rock the boat baby

by Diane Thompson (U. Arizona)
Taking the reins of the coral drilling operations for the remainder of the trip from Kim, I had some pretty big shoes to fill.  And still feeling pretty under the weather from some unknown traveler’s sickness that had me ill for the past few days, I was unsure of how today would go.  We had a pretty ambitious agenda that involved taking the boat all the way to its southern limit to scout for fossil corals along the shores and to drill a couple more coral heads. 

Drilling a small lobey Porites for comparison with the other cores.  Note: I'm not *trying* to look like a cool kid, but rather holding on to the dead underside of the colony to keep stable.

The sky ahead looked ominous, making it clear that we were once again in for a very wet, cold day on the boat.  We all thanked Jess for her effective rain dance, which seems to work all too well on boat days and not well enough on the long hot days on land.  Despite the rain (and a minor distraction caused by a pod of dolphins swimming by), we spotted a number of great rubble fields of fossil corals on the shores that would be great to sample on future trips.  That is, assuming Kim gets very creative on how to get there, since much of the south side of the island is inaccessible by either truck or boat.  Maybe she could use this as justification to purchase a lab helicopter?  Seems totally reasonable to me (I’m sure NOAA will think so too)!

Arriving at the southern side of the island, it was immediately clear why this was the furthest limit of the small boat operated by Dive Kiribati—the conditions were quite rough.  Surviving the huge swells like a true sailor, Jess officially earned the rights to change her field nickname from “Chucky”.   We decided to drill a large head here, in hopes of getting another core around 2 feet in length, and quickly found out the conditions in the water were just as exciting.  Jess and Liz had to fight the surface current and waves to help shuttle air to us for powering the drill.  And underwater, the surge was quite powerful and made the drilling operations quite “interesting".  Especially considering the drill gods decided to continue frowning upon us. 

After the drill had died (again) while drilling a fossil coral in town yesterday, we had decided to move up the modern coral drilling trip previously planned for later in the week.  We just couldn’t risk both drills failing before getting the modern coral cores we had set out for.   Kim had arranged for two more drills to come on today’s flight, but we weren’t sure if they would make it, so we had to push on with what we had. 

I had hardly broken the surface of the coral before the drill stopped turning.  I tried again, and nothing.  So we changed over to the back-up drill quickly underwater, and were relieved when it seemed to be working fine.  Then suddenly, a ways into the core, the drill literally fell apart and the washer holding the two pieces together went tumbling to the bottom of the reef.  The joint that had been operated on earlier in the week had come loose.  Luckily, we were able to recover the washer and put it all back together.  However, in the process of trying to do this underwater in the strong surge, I managed to somehow bump my incredible assistant, Boata, in the head with the drill bit.  Yikes.  Taking a deep breath, I proceeded to drill down core reminding myself of my favorite saying from my Dad: “If it were easy, any darn fool could do it.”   Thankfully, the drill decided to cooperate, and the drilling went very smoothly from here on out.  We were able to get 30 inches of core, not only meeting our goal, but also giving us the longest core of the expedition thus far! Unfortunately, only 23 inches was a Porites.  The bottom 7 inches was of another coral, which based on the growth rate of the Porites, probably died in the strong 1982/1983 El Niño event!  That in itself is very interesting and tells us a lot about the climate and state of the reef after that large event.

On the way back we took another short core and filled some of our previous drill holes with cement plugs to allow the coral to grow over the hole.  All in all, it was a very fun and successful day.  For the next two days, we’re off to the southern limit of the road via truck to hunt for more fossil corals.  But first, Jess and I need a lesson on stick.  Oh, and we’ll get to learn while driving on the left side of the road from the right side of the truck.  This should be interesting….tune in for an action packed blog when we return in a couple of days!

Drilling Around Town (Going Viral on Christmas … the Old Fashioned Way)

by Hussein Sayani

Having resuscitated both the drills the night before, we [except Chucky] set out on a quick morning dive. The goal was to try and drill a two foot modern core which would hopefully get us past the 97-98 El Nino. Our target coral looked very promising, but was unfortunately much deeper than previous heads drilled. That wasn’t a problem for us as we’ve become master innovators (just check out our ghetto fabulous ride a few posts down). We quickly rigged up an elaborate system consisting of ropes, a buoy (we rescued from the Bay of Wrecks) and a snorkeler to help shuttle air tanks from the boat to the drill site. Everything went well, but we were only able to retrieve a 20 inch long core.

Onto the afternoon:
As our avid readers may remember, we spent just two hellish days of scouring the eastern beaches of the island, mostly along the ominous sounding (but ultimately disappointing) Bay of Wrecks, and had almost given up hope of finding any large fossil Porites corals. However, fortune smiled upon us on the bumpy ride home when Diane, aka Coony, spotted a large Porites simply ‘chilling’ in someone’s yard. Jackpot! With fewer eyes on the road (and the road bumps, ouch!), we began noticing the abundance of large fossil corals being used around town to line flower beds, stacked to build walls, etc.

Diane and Kim checked various locals if we could take/drill some of the rocks in their yard.  Most were very accommodating, especially one very helpful man who not only offered the rocks sitting in front of his house, but pointed out other potential drill targets in his back yard.  One lady, however, was very adamant that we return the corals even after they had a hole in them.

So, we crammed 10 tanks of air, two large boxes, some buckets, and a drill into our rust bucket and drove to our first in-town drill site near the Tennessee Primary School. The drilling operation began just as school was letting out, so we quickly built up a crowd of eager onlookers.  Our first audience was a group of small boys who were very curious about the hole we had just put into a large fossil coral.  Their curiosity was short lived as one of the little boys yelled “TRUCK!” and they all ran towards the road and very impressively catapulted themselves into a moving truck.  This is apparently is probably the equivalent of a school bus on Christmas Island, as we saw many of the kids do same thing all afternoon. Pretty soon we were surrounded by kids of all ages and even a few adults. The large crowd drew even more people in and just like that we had gone viral on Christmas Island.

As our audience continued to grow, we began wondering what they made of us – 5 very sweaty strangers, drilling rock, vigorously working a water pump, and shuttling tanks of air and buckets of water back and forth.

A Smiling Rain God

by Jess Conroy
With the departure of our fearless leader, it’s my turn to blog from the field.  I was lucky enough to join in on this coral collecting trip to help out and to pursue my own research agenda. As a postdoc in Kim’s lab, the project I’ve developed is based on collecting seawater and rainwaters from across the tropical Pacific. I will be measuring the chemistry of these water samples--specifically, how the isotopic values of hydrogen and oxygen change over time. These numbers are fascinating, and can tell us a whole lot about the hydrologic cycle in this part of the world. For example, at Christmas, changes in these values can tell us whether it’s been wet or dry, or if ocean water is sloshing in from the west of the island—changes that are today most often linked to El Nino and La Nina. More importantly, what these water isotopes are saying is recorded by the local corals. The geochemical message embedded in coral skeletons is one way coral paleoclimatologists like Kim, Diane, and Hussein reconstruct past climate change.

Here I am taking a seawater sample in the yard of Dive Kiribati,
our home on Christmas Island.

So you can imagine then it’s really important to understand just how these isotopic values in rain and ocean water vary, and how they relate to modern climate measurements, like ocean salinity or rainfall amount. Trouble is, there are hardly any of these measurements available from this part of the world. Yikes!  My research is a major attempt to start plugging this hole between paleoclimate isotope records and modern climate data.

As Kim and crew have struggled with the drill, my progress in the field has been pretty seamless. I braved the rats and rat turds in the fuse box, and got the weather station up and running.  I set up my rain collector, and I’ve been taking lots of seawater and rainfall samples.  It’s normally pretty dry here, but apparently my [Sailor Jerry/sunstroke-induced] rain dance was effective: it has rained everyday we’ve been on the island, providing me with lots more data points than I expected. Another bonus: there is no sweeter relief after hours of hot fossil coral hunting than a gentle Pacific rain shower.

However, storms have also led to swelling seas, and swelling stomach contents, so not everything has been perfect. And I completely fumbled my first attempt at sampling rain waters through a single rain event. I frantically started to get my sampling materials together one afternoon as it started pouring, but without a stopwatch of any sort on hand (my cheapo sport watch oddly stopped working just as we crossed the dateline), I forgot to time the rate of drips off the roof. Thus, I collected a lot of water samples without any quantitative idea of how much it rained. I feel only marginally better that on the last Borneo expedition, they forgot to do this too. Luckily I got to remedy this mistake yesterday, and hopefully I will get some more chances in the coming week, but stay tuned for more face palms.

Houston, we have a problem

What we were supposed to be doing today!

The day started well - a bright sunny morning, 16 SCUBA tanks, and a good idea where the larger Porites colonies are growing on the reef. So we headed out, chipper and optimistic, although looking down the barrel at a huge 10-hr day of drilling underwater.

We chose a beautiful colony that Liz had found (this girl is a veritable magnet for large coral colonies!) and maneuvered the boat into place over the coral head through trial and error. And at the 11th hour, just as we were donning our SCUBA gear, we realized that the pneumatic drill wasn't turning. Not even a bit. It was absolutely positively rusted through and through, frozen solid. Nothing to be done but turn around and curse silently (for the most part) all the way back to base, knowing full well that this could be the de facto end of our coral collection on this expedition. It was grim, to say the least. What idiots we had been not to run lubricant through the drill 2 days ago after our first dives! We had probably all thought about it, but nobody really took the reins and did it, probably because we were high from our success and felt invincible. A serious smack-down was headed our way, and the karmatic powers that be certainly chose an effective way to deliver the message - there is no single piece of equipment more important than The Drill. In fact, we brought TWO along just in case one gave out. But of course we had tested both of them in seawater when we thought the drill was broken, so they were both in the exact same condition - utterly useless.
We got on the internet and managed to get the maker on the custom-made drills on the phone, and he basically laughed when we told him what had happened (a most unwelcome response, as you might imagine). He said our only bet was to soak the drills overnight in WD40 and pray. So we bought a can of WD40 for $18.20 (!!!!) and went about trying to get the drills unstuck. By lunchtime I was climbing the walls with anxiety, so we loaded up for a fossil coral hunt on nearby beaches while we waited and prayed for the God of WD40 to smile upon us. The trip did the trick - we found many many Porites fossils and I had a good time talking to the team about how to avoid unhappy corals (corals grow funny when they are smushed up against the water's surface, and we'd like to avoid these for paleoclimate). And everyone worked their hearts out under sweltering mid-day sun, bless them. It was hard to stay in a funk for long.

When we got back, things hadn't changed, so I initiated Operation Christmas Drill, firing off a bunch of desperate e-mails to various corners of the world in a desperate attempt to get a new pneumatic drill shipped down here on the next plane in two day's time. And then I got serious. The local guys began an in-depth project to change the nonexistent brake pads on the mini-truck, and I took inspiration from them to attempt a full-scale dismantling of the drill itself. I enlisted Hussein to help me keep track of parts and think through rough patches. And piece by piece, using vice grips, pipe wrenches, and lots of WD40, the drill came apart! We cleaned all the parts off with (you guessed it) WD40 and began to reassemble. We hooked it up the air, opened the valve up to full throttle, and let her rip. At first nothing happened, but then in a shower of blackened WD40, it spun! An hour later we had freed the 2^nd drill from its rusty grave too! So needless to say, I could have done without that little adventure today, but as they say, all’s well that ends well. Tomorrow we’ll drill that nice Porites on the reef from this morning, and carry on with the drilling of fossil corals in the village in the afternoon. A full day, but believe me, I will be smiling with every single revolution of that drill. If anyone ever needs to know what’s inside a pneumatic drill, Hussein and I can give you a detailed overview any day.

Billions and billions of corals

Liz Wiggins showing off her humongous fossil coral,
a mystery species that grows 1cm/yr. The piece she
found will likely yield 50 years of continuous record.
No idea when it grew, we'll have to wait for U/Th
radiometric dates to tell us. 

Sorry not to post for a few days. It takes forever with the internet connection we have, and we have been BUSY collecting corals.

Our mini-truck with rigged rain fly, providing much-needed
shade.

The last two days we've been over on the windward side of the island, called "Bay of Wrecks", scouting the 20km-long beach for fossil coral rubble like those pieces shown in the photo. The first day we took our rust-bucket mini-truck with no shade, rigging a rain fly over the back in a desperate attempt to get the team some shade (see photo). We near-wilted in the sun. Everyone got sunburned.

Day 2 we were a bit better prepared, both mentally and physically. Liz broke out the Southern Belle hat (see photo), so you know it was serious sun. We also had rented a huge truck with a pavilion over the back for the day, from a local named Mopuola, who turns out to have a BS from Tuvalu and speaks perfect English. I only found all this out *after* I had bungled my way through an elaborate mime routine to communicate my desire to rent his truck. What an idiot. My miming skills aren't really coming in handy here, most people speak fairly good English. For example, we had found some rather large Porites corals (our target of interest for paleoclimate reconstruction) in some of the village gardens. We went to bungle our way through a conversation, and found ourselves speaking with a bunch of English-proficient villagers. They were very curious what we were doing with their rocks, and some of them wanted them back after we poked holes in them. We tried to explain our purposes, things clicked a bit better when we said "El Nino", as their lives are at the mercy of the El Nino-Southern Oscillation extremes here. We will be giving some presentations in the local high schools tomorrow, to explain to them the uniquely valuable records that are strewn about their gardens, white gold to us. We will have to spend a fevered few days drilling the larger Porites heads we found scattered throughout the village. That haul will add to over 400 fossil coral samples we collected yesterday! We will definitely top 1000 on this trip.

Why do we need so many fossil corals, you might ask? For a couple reasons. One, we do not know when any of these corals grew, and we'd really like to have good coverage through some key intervals of time. One target is the so-called Medieval Climate Anomaly, roughly 1000 years ago, when mega-droughts ravaged the western United States, and parts of the mid- to high-latitude Northern Hemisphere were warmer than the rest of the millennium. Theory and models suggest that cooler-than-average tropical Pacific temperatures may have contributed to the global climate reorganization, but data in support of this hypothesis (including our original fossil coral reconstruction from nearby Palmyra Island) have been scant and oftentimes conflicting. Hussein will be targeting this interval for his dissertation research, yet we only have 2-3 sequences in our entire collection that date to this interval at present. Hopefully we can provide 10 or so more. The second reason for the over-the-top collection strategy is to make sure that we have multiple individuals from the same time interval, rather than just one or two. That is necessary because we have observed, along with many other coral paleofolk, that contemporaneous corals are offset from each other in oxygen isotopes (the "proxy" that we use to track past climate changes in the corals). We do not yet know why this is the case, but it being the case, we have to beat down that error with large numbers of corals, trusting that the average of many corals is a better estimate of past climate than any single individual.

And so we collect hundreds and hundreds of samples. I should say that this is not common practice in the field. We usually would be happy to publish a reconstruction with 5-10 samples over a given time period. My first paper contained 8 fossil coral sequences, and was considered over-the-top in terms of numbers of samples. The paper we are writing up right now, spanning the last 7 thousand years, will contain 15 sequences. The project we are launching with this fieldwork is designed to deliver hundreds of sequences for our next papers. A high-volume enterprise, for sure, and very expensive. Fingers crossed that NSF will eventually fund the lab component of our work!

For now, I'm off to breakfast and then a long day of diving. We'll target the usual suspect, Porites, as well as a living colony of the mystery species we collected so many of yesterday (pictured with Liz). It's a stunning day, light wind and sunny, so it should be pleasant out there.

Quote of the day:  "There is no 'I' in fieldwork." [Diane Thompson, pausing for a breather while hauling, together with 3 other people, a 200lb box of fossil coral across a football field-sized stretch of sand to the truck.]

Drill, Baby, Drill

For those of you who read the last post, you'll know that we were hoping against hope to drill 1-2 cores yesterday at great effort. Well, we woke up early and began loading up the boat. Upon seeing the rusted drill parts up close, I noticed that the actual drill barrel was *slightly* misaligned. A wave of realization washed over me:  if there was the slightest wobble in the drill, we would be cutting side-to-side as much as we were cutting down! I took apart the drill barrel and reassembled, careful to make sure everything was flush. Tightening it up, it looked a lot better, but I still was unsure exactly how much of our previous problems were caused by the minor misalignment.

It turns out that small adjustment was a complete game-changer! We drilled 3 cores in 2 long dives, the longest of which was 22", for a grand total of 52" drilled! Now that's what I call a successful day. Of course the day had its challenges. Jess earned her field name "Chucky" after a serious bout with sea-sickness during the morning's drill session. The rest of the support crew fared marginally better. The afternoon's trip was bitter cold, it was raining the entire way there (a 20 minute boat ride). [A side note:  it's been raining a ton here lately, much more than historical averages. The locals confirm it's been an incredibly rainy spring. A quick look at the latest data from the TOGA-TAO array - a network of ocean buoys stretching from South America to the West Pacific on either side of the equator - reveals that the central tropical Pacific is unusually cool now, coming off last season's La Nina event. In short, that should mean that it's raining less, not more, across the Line Islands. The cause of the mystery rains will have to wait until I return, when I have access to satellite data from the last months. I note, however, than former graduate student Intan Suci-Nurhati and I published a paper documenting a trend in a long coral record from nearby Palmyra Island that implies a significant increase in rainfall over the last 30 years. But regardless, this weird spring surely cannot be fully explained by the trend we uncovered.]

At any rate, the drilling operations continued, amid a downpour and a seriously pissed off ocean. We couldn't keep our snorkels clear while hunting for our next coral victim, washed by whitecaps every few seconds. Getting underwater was very welcome - no rain and lots less swell to deal with. Diane took the reins on the drilling, and mowed slowly but steadily down core. We had a couple bumps in the road, but by the time we surfaced we were carrying our longest core yet. We were giddy. Diane mentioned that we hadn't yet reached bottom on the coral - did we want to go back down for one last push? We had some air, but only for 10 minutes or so. Hussein measured our haul - it came up just shy of the target length - short by 4" or so. I agreed to go back down. Drilling again, we quickly punched through the base of the hole, with plenty of air to spare. While surfacing, a white glimmer on the reef flashed in the corner of my eye. It was a 4" section of coral core! We had come *this close* to leaving it to rot on the reef. I quickly grabbed it and surfaced, knowing that we now had achieved our target length. We came back exhausted but triumphant, having far exceeded our day's scientific goals.

Time for a party! We had been invited to a local get-together at the Captain Cook hotel (a 2-star accommodation on the north side of the island - I had the pleasure of staying there in previous expeditions). After paying AUS$5 each, we settled in at a table and watched local crooners and dancers alternate on the stage. We had smuggled a bottle of nice rum in, so we purchased some Coke and relaxed. There were a couple of white folk there when we entered, but soon they left and it was just us and about 100+ locals, who became very engrossed in a protracted skit (some sort of love triangle) that had everyone doubled over with laughter. Hussein was mercilessly hit on by a local guy, who identified himself to us as a police detective complete with a laminated badge that looked like it had been printed on a 1990's vintage inkjet printer, the colors now reduced to faded oranges and yellows. Our hostess here at Dive Kiribas, Anami, was dressed to kill and stayed much later than us - she had rented a room for her family at the Captain Cook. When Liz started falling asleep in her chair, I knew it was time to leave. On the way back I ran over more than 3 crabs who were scuttling across the road (Hussein swears it was 5), but I avoided at least 5, so it could have been a lot worse.

Today we're off to the far side of the island by truck (a 1980's rust-bucket with absolutely no shocks left), in search of fossil corals. We'll take water samples along the way, and try not to break down. We'll take radios as well as plenty of water and sunscreen, just in case. It looks like it won't rain today, which is a lucky break for those who will be sitting in the back of the truck all day. Although I daresay that by the end of the day, they'll be begging for a good rain to cool them off. Wish us luck as we turn our attention to the fossil realm, in search of climate signals from thousands of years ago.
[I'll post a bunch of photos later today, when I have the time to wait for the painfully long uploads to complete. Liz got some great shots of the drilling, so check back soon.]

And we drilled (drum roll, please)... 3 inches!

We awoke to a beautiful day here at our new home, Dive Kiribas, a collection of 5 thatched huts complete with our own private beach. The best part about our accommodations is the shower, which is made out of fossil corals (see photo).

The day’s agenda was ambitious. We had to touch base with the Christmas Island conservation officials early in the morning, test our drill during a test dive, and snorkel across reefs in the afternoon searching for healthy medium-sized coral colonies to drill. The officials were incredibly amenable to our plans, and surprisingly unconcerned about the drilling we would do in the next days. They instead were keen to monitor our movements in the more remote parts of the island, where nesting seabirds can be disturbed. Of course, to ensure the preservation of the colonies we drill, we will plug each drill hole with a cement plug that the coral will grow around and eventually seal up over several years.

Testing the coral drill on shore

Turning our attention to the test drill, we quickly realized that the new pneumatic (air-powered) coral drill was significantly less powerful than the hydraulic coral drill that I have used on all my previous expeditions. We wondered whether it would cut a pristine modern coral colony more easily than the hardened rubble we tested on our beach (see photo). Our objective is to drill 5-6 cores of 24" each during the trip. We already have a couple of very long cores that end in the 1990’s, so we need to get back to the 1980’s to splice into these longer cores. Christmas corals grow just under 1" per year, so if we need 25+ years of core we’ll have to drill 24" or so of core. A paultry goal by coral paleoclimatology standards (we typically target heads that are >6’ tall), but we this time our goal is to assess the reproducibility of overlapping coral cores in the very recent past, when plentiful instrumental climate records exist, rather than extend back many decades with a single core, as is common practice.

Kim & Diane showing off their day's coral haul

Having identified a suitable test specimen in 20’ of water, Diane Thompson and I descended to begin our first drill attempt. It was short and not very sweet – we blew through the two SCUBA tanks we had brought in under 10 minutes of drilling, with only 3" of core to show for our efforts! (see photo) Keep in mind that we could easily drill 12" of core in 10 minutes with the trusty hydraulic rig. We were crushed. How would we ever get the 24" of core that we needed, let alone 5-6 different cores? We limped back to base determined to fix what was surely a gaping leak in the air lines. And we leak-tested, swapped parts, scratched our heads, and ultimately came to the conclusion that we would need A LOT of air tanks to drill a single core. A quick e-mail to my past student Intan Suci-Nurhati, who has definitely surpassed her mentor in meters of coral drilled with a pneumatic drill, confirmed our suspicions. We’d need 10+ tanks to achieve our target core length, hopefully over the course of a single 45-minute dive. We spent most of the rest of the day dreaming up a rope-pulley system designed to get 10 tanks down to 30’ and back up at 5-minute intervals. We will "brute-force" it this time, and cross our fingers for cooperative weather and a smooth tank-shuttling operation by our trusty team. We’ll be very lucky to get 1-2 useable cores in 1-2 dives tomorrow. Boy do I miss my hydraulic rig, sitting in 4 crates back in Atlanta. Of course the grass is always greener – I no doubt would be cursing the cumbersome, heavy, loud, smelly engine if it were here instead.

Oh, and number of shark sightings today: 0. Very sad but predictable. Tomorrow we’ll be farther from the island’s various villages, so I remain hopeful that we’ll see signs of a healthy, vibrant reef ecosystem on a different part of the island.

Out for an end-of-day snorkel (and water sample). From left:  Kim Cobb, Hussein Sayani,
Jess Conroy, Liz Wiggins, and Diane Thompson

Quote of the day: "If I were to throw up, where would be the best place for me to do that?" [Liz Wiggins, on getting back onto land after a long boat ride. She found her land legs after a few minutes. Funny, most people don’t realize that it’s often the getting-back-on-land part that can put you over the edge.]

Are we shark bait?

We're on the airplane to Christmas Island now, armed with hard-copy proof that we have a return flight back to Honolulu. We got a good chuckle out of this - Christmas immigration apparently must see a printed itinerary of our return flight, ostensibly to ensure that we have no intention of staying forever! No need to worry - Hussein doubts he can survive 2 weeks without 4G, much less the rest of his life.

En route to the airport, we had a lively discussion about various parents worried about their offspring being devoured by sharks (among other things) during the course of our expedition. I believe the direct quote was "Y'all are going to be shark bait, for sure".  Let me assure all the parents of our fledgeling scientists that nobody be will eaten on this trip. In all my years of diving and snorkeling on these reefs, I have never had cause for concern, with one exception. On a research cruise in 1998, I jumped in the water at Jarvis Island (an uninhabited US possession more remote than Christmas) and instantly drew 50+ curious sharks. I spent less than a minute contemplating whether to continue the dive, and found myself unable to suppress my instinctive fear at their excited collective mass. I have never been so grateful to exit the water. More recent dives across the Line Islands tell of a vastly changed landscape for the Pacific's shark populations - one of massive declines in the face of overfishing fueled by Asia's appetite for shark fin soup, which is prized as an aphrodisiac of sorts.  Long-liners from Asia comb the bountiful fisheries across the Line Islands (I have personally observed this on numerous occasions), some of them  no doubt compensating the Republic of Kiribati and some operating literally under the radar. Once they catch a shark, they cut off its dorsal fin and often throw the animal back in the sea to die, saving money on transporting a relatively low-value meat back across the Pacific. It is a practice that has been widely condemned, but a robust market for the delicacy, combined with the difficulty of enforcing fishing practices in the most remote areas of the Pacific, ensure that shark finning will continue to wreck havoc on the Pacific's shark populations. Ecologists tout the importance of so-called "keystone predators" (those near the top of the food chain) for the maintenance of healthy marine ecosystems, so it stands to reason that the decline of the sharks across the Line Islands will eventually impact the corals themselves. This stress will add to stressors associated with the local island populations (untreated sewage runoff, illicit trade in aquarium fish, and overfishing of smaller fish who keep algal overgrowths at bay) as well as those associated with climate change (declining pH and rising temperatures). I have only just begun to contemplate how to marry our coral climate reconstruction research with ecological studies of reef health to track coral "health" through time, through natural climate fluctuations such as El Nino events and over the next decades of anthropogenic climate change. A new graduate student named Pamela Grothe will be joining the lab this fall, and will work closely with Scripps Inst. of Oceanography coral reef ecologist Stuart Sandin who has been working on Line Island reef systems since 2005. We are hopeful that we can combine each other's data and approaches to learn more about coral response to environmental stressors, ideally informing coral reef management and climate change mitigation policies.

So unlikely as it is, it would warm my heart to see a healthy shark population at Christmas Island. Definitely check back for our best "shark bait" photos in coming days!

All's well that begins well

We are officially en route to the central tropical Pacific, where we will collect modern and fossil corals, rainwaters, and seawaters in support of our paleoclimate reconstructions from this area. The field team includes Postdoctoral Fellow Jess Conroy, University of Arizona graduate student Diane Thompson, Georgia Tech graduate student Hussein Sayani, and undergraduate research fellow Elizabeth Wiggins. We are especially lucky that Hussein and Liz will be with us on the weekly flight to Christmas Island tomorrow, considering that their tickets to Honolulu apparently didn’t exist when we went to check in this morning! One occasion that money (and a lot of luck) can buy you happiness. Many thanks to the kind folks at Delta, and to the hundreds of ATL passengers waiting at security that we cut in front of to get Hussein and Liz on their flight. There’s never a dull moment launching an expedition, in my experience.

Here are some maps of our destination - Christmas Island (2N, 157W).

Googlemap of Christmas Island (2N, 157W)

Why Christmas Island? Christmas is located in the very middle of the Pacific Ocean, at the heart of the El Nino-Southern Oscillation, a far-reaching source of year-to-year global climate variability. Warmer-than-average sea-surface temperatures associated with El Nino events cause widespread flooding along the western coast of the Americas and bring drought to many areas in and around the western tropical Pacific. La Nina cool extremes have largely the opposite effects. As high-quality instrumental records of climate in this region only extend back 60 years or so, our lab has generated multiple coral-based reconstructions that extend back many centuries. These records contain a rich history of central tropical Pacific climate variability, capturing El Nino-Southern Oscillation extremes, natural decadal-scale variability, as well as late 20th century trends associated with anthropogenic climate change. Such records are constructed from so-called “fossil” corals, found lying on beaches at Christmas and neighboring islands. We calibrate the oxygen isotopic-based climate signal in the corals using “modern” corals collected via SCUBA. On this trip we will collect hundreds (thousands?!?) of small fossil coral samples and several modern coral cores. The second major objective of this trip is to collect dozens of rainwater and seawater samples for oxygen isotopic analysis, and set up a long-term water collection program on the island. Such data will help us understand how regional temperature and rainfall changes are recorded in the oxygen isotopic variations of the island’s corals. We will be posting more detailed explanations of each of our scientific objectives as we tackle them. Hopefully this morning’s antics are not a prelude of things to come, but in my experience fieldwork is full of surprises, both good and bad.