Fieldwork in the Atacama Desert, Chile

Thursday 13 December 2012

Cladocora caespitosa; from reefs to crystals (in pictures)

 As this will likely be my last post of the year and nobody wants too much science this close to Christmas, I thought I'd just use it to show some pretty pictures of the corals (Cladocora caespitosa) I've been working on. As you scroll down the level of zoom increases from full reef to microscopic crystal scale, enjoy...
Mljet C. caespitosa bank, Croatia; the only known example of a modern C. caepitosa buildup comparable to a tropical reef (Photo courtesy of P. Kruzic)

Living C. caespitosa with extended feeding polyps (Photo courtesy of P. Kruzic)

Mid-Holocene (6-10,000 years old) fossil C. caespitosa, Mavra Litharia Reef, Greece (trowel for scale), they don't look quite so nice by the time I get to them as they've been dead for a few thousand years and uplifted out of the sea.

Sample hacked off the above locality

Sectioned isolated corallite, ready for analysis (approx. 45mm long)


Optical binocular microscope images of sectioned corallite showing the complex internal structure of the septa, the brown staining is most likely due to contamination from iron-rich groundwaters percolating through the porous septa and so these regions must be removed before analysis to leave just the solid outer wall behind (corallite is approx. 8mm wide)

False colour optical image of a horizontally cross sectioned modern corallite stem showing the spoke-like structure of the septal region (larger sample approx. 7.5mm diameter)


Same cross sections as above but viewed under the scanning electron microscope (SEM) , lower image shows secondary cements infilling some of the pore spaces between the septa showing that these areas do not all grow at the same time.

SEM image of the septa seen from side view
SEM images zoomed right in to see the individual crystals of primary aragonite that make up the coral. The primary aragonite is unstable and prone to breaking down over time, if this happens the original geochemical signals recorded by the growing coral are lost and they are useless to me, but these look like very good samples for analysis.

If the aragonite does break down, more stable secondary calcite crystals (shown here) replace them, this sample would be too altered to be of any use for analysis.




Sunday 2 December 2012

To infinity and...Hertfordshire?

BLEAT logo (by J. Shirley)


So yesterday (01/12/2012) the first mission of UEA BLEAT (the University of East Anglia Balloon Launch and Exploration Team) was carried out.

0500hours: 6hours to high altitude balloon launch

The day started at 5am when Commander Rushby, Admiral von Glasow, Captain Mills and myself (Chief Engineer Royle) loaded up the launch convoy from the University of East Anglia’s Environmental Sciences department. It was dark, bitterly cold and I hadn't been to sleep yet having arrived at the department straight from a party that was still going when I left after 4. Commander Rushby, on the other hand, had spent the night sleeping under his desk in the office, although somehow we were both surprisingly cheerful and optimistic about the day ahead.

5am: Ready to go, once Commander Rushby finishes his breakfast

0530hours: 5hours and 30minutes to launch

The launch convoy of Admiral von Glasow (the only person trained to transport pressurised gases) in the Helium Transport Vehicle and the other 3 of us in the Mobile Command Centre (Captain Mills’s ancient camper van) headed off by 5:30 towards the launch site in Burton-Upon -Trent. Most of my journey was spent napping on the sofa in the back of the van but from what I did see we appeared to get there without a hitch – aside from the very poor decision to eat disgusting microwaved petrol station sausage butties for breakfast.

1000hours: 1hour to launch

We arrived at the launch site, Shobnall Leisure Centre, and, after Commander Rushby had made final pre-flight checks with all the relevant authorities, made final preparations for launch. Inflating the balloon – after having to borrow a bigger spanner from the very helpful staff at the centre as the one we had brought didn't fit around the gas regulator – starting up the cameras, adding yet more duct tape to secure the payload and tying all the components of the 20m long high altitude payload launch and recovery system (balloon, parachute, ‘spacebox’ capsule, radiosonde tracking system) together.

Inflating the balloon by the launch convoy, Mobile Command Centre on left
Me with the balloon

1100hours: 0hour, liftoff

Successful launch from the middle of a football field, watched on by confused dog walkers and runners – although none more surprised than us that it worked perfectly. As we watched the balloon climb rapidly (at around 8m/s) and disappear into the sky, the tracking system kicked in and, once the radio receiver was taped to the roof and the mobile command centre was set up in the back of the van, we were ready to go.

Commander Rushby and Admiral von Glasow readying the launch

And it's away


1130hours: 0hours 30minutes flight time

We sped down the M11 tracking the balloon in real time, passing the sporadically gained balloon’s elevation, azimuth and distance-from-launch-site data on to Science Officer Chylik at Mission Control. Here this data was converted to latitude and longitude data and constantly updating predictions were made about the balloon’s flight path and landing area. As all we had to go on was the pressure and temperature data to guesstimate heights we just headed SW and carried on relaying the data as it came in.

1200hours: 1hour 00minutes flight time

After a rather relaxed morning and a pub lunch somewhere near Harlow, the Chase Team (driven by Captain Gooch, led by Tactical Officer Surl and completed by Ensigns Huezé, Davies and van der Weil) set off fearlessly in hot pursuit of the balloon which had been predicted to come down between Welwyn Garden City and Cheshunt.

The Chase Team having a very taxing morning (photo by L. Surl)


1243hours: 1hour 43minutes flight time

As I sat in the back of the speeding (not literally) Mobile Command Centre, intensely staring at the computer tracking readouts, the pressure and temperature data which had both gradually been falling and had reached around 13hPa and -67oC respectively suddenly started increasing; burst had occurred at approximately 28,210m over Northhampton. The slow rate of increase suggested that the parachute had deployed successfully and this was confirmed when the radiosonde started to report actual altitude data showing a perfect descent rate of 4m/s. Science Officer Chylik came into his own at this point, constantly updating predictions while we parked up at Watford Gap services to increase radio signal accuracy.


Professor von Glasow attempting to boost signal accuracy



Mobile Command Centre in action trying to pinpoint the balloon's last known loacation

1315hours: 2hours 15minutes flight time

Unfortunately we lost radio contact around 0115hours at approximately 2500m altitude and so the landing predictions were somewhere within a rather large ellipse around Oaklands Forest, Hertfordshire. The Chase Team were rapidly deployed to search this area and Mobile Command sped down the motorway to assist.

Chase Team in action

1350hours: 0hours 40minutes after losing contact; 2hours to sunset

The chase team arrived in the predicted landing area and proceeded to search on foot, splitting into 2 search parties to cover ground more quickly.

1500hours: 1hour 10minutes after losing contact; 50minutes to sunset

Mobile Command also reached the search area, searched the dense woodland below the balloon’s last known location and tried to recruit as many passing dog walkers as possible to keep an eye out for it. Even though we knew the odds were greatly against us finding anything in this terrain we continued tirelessly until it got too dark to see around 1600hours and were finally forced to concede defeat. Headed to the local pub to meet up with the Chase Team, having to rely on someone finding the box for us and the contact details on the side having survived the trip.

2000hours: 6hours 10minutes after losing contact; been awake for 37hours

Finally arrived back at ground control for commiseration drinks and pizza, while we did not recover the box on the day all is not yet lost and Hertfordshire’s local police and media have been notified in case anyone reports seeing anything strange in the sky or actually finds it. Also, this was still a very successful shakedown flight showing us that the payload delivery, high altitude tracking and landing system worked very effectively and that for future missions we need to develop a way of tracking the box’s ground position – most likely by investing in a cheap Android mobile phone with an app that can relay its co-ordinates by text message.

Full live tweet coverage of the launch and recovery attempt can be found at @UEABLEAT and will also be covered in next week’s issue of Concrete, all photographs I took on the day are here.