Today we have swapped roles. Hannah is now learning the soil gas sampling that I did yesterday and I will be doing the CO2 efflux and surface temperatures using the accumulation chamber method.
The surface temperatures are pretty self explanatory. A thermo-coupler is used with an 11cm probe and a 40cm probe. Both probes a pushed in to soft ground and left to acclimatise, during which the ambient temperature using a second thermo-coupler is recorded and the accumulation chamber is set up.
The accumulation chamber equipment is set up to communicate via Bluetooth to a PDA. The PDA is used to control the motor inside the equipment and collect the data recorded in situ. Once the motor has been turned on, the accumulation chamber is left to draw in air for 10 seconds, this gives the operator time to check the equipment is registering atmospheric CO2. After 10 seconds the chamber is placed on the ground and made as air tight as possible, it is then left undisturbed for 120 seconds. The data collected can be observed in real time over the collection period and becomes significant when the regressions (R2) exceed 0.5, the efflux is recorded as ppm/s (parts per million per second). All the information is saved on the PDA at every site, it is also written down and transferred to excel at the end of every day.
CO2 efflux in situ gas values measuring using the accumulation chamber method
We managed to finish a little earlier than expected so we drove the long way back to the accommodation taking in the Taburiente caldera visitors centre and seeing Pico de Borigoyo, the highest point of the Cumbre Vieja volcanic rift.
Me with Pico de Birigoyo the highest point of Cumbre Vieja
Every day is an adventure!
Buenas noches de La Palma!