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• .xls ()

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http://www.bgs.ac.uk/ukccs/accessions/index.html#item35609  

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dataset Dataset

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Samples of sediment, pore waters and water column were taken in 4 zones i) pre-injection, ii) during the gas injection, and iii) during 4 sampling campaigns conducted up to 1 year post-injection: Zone 1: Directly above the CO2 injection point Zone 2: 25 m away from the injection point Zone 3: 75 m away from the injection point Zone 4: 450 m away from the injection point A series of sediment cores (~20-25 cm long) were collected from the 4 zones that had different distance to the CO2 injection point. At each sampling campaign three sediment cores were collected in perspex tubes (5 cm inner diameter) from each zone and on each sampling campaign by Scuba diving and immediately transferred for processing to a temperature controlled room set to the in situ temperature (usually ~10ºC). One core was sub-sampled for solid phase sediment analyses and the remaining two cores were used for sediment pore water extraction. For solid phase analysis, the sediment cores were sliced at 2 cm depth intervals. A sub-sample (3 mL) of each section was transferred into a glass headspace vial containing 5 mL of 1 mol L-1 sodium hydroxide and crimp-sealed for methane analysis. Sub-samples for porosity and grain size were stored in pre-weighed plastic containers at 4ºC and the remainder of the sediment sample was freeze-dried for XRF analysis. Water samples were collected from onboard the research vessel Seòl Mara using a 5L Niskin bottle. Water samples were taken from 5 depths, ranging from 2 m below the sea surface to 1 m above the seafloor, with the absolute depth depending on the tidal range. Sub-samples were transferred into gas tight glass vials without headspace for DIC, TA and dissolved oxygen analyses. Additional sub-samples were frozen in plastic bottles for nutrient analyses. The major and minor element composition of the sediments was determined by X-ray fluorescence on fused glass beads for the major elements and on pellets pressed into bricks for the minor elements. Total inorganic carbon (TIC) and total carbon (TC) concentrations were measured with a CO2 coulometer equipped with an acidification module, and organic carbon (Corg) was calculated by subtracting the acid soluble fraction from the bulk carbon. Porosity was determined by mass difference between the wet sediment, and sediment dried in the oven at 60ºC for a minimum of 72 hours, assuming a sediment density of 2.6 g cm-3. Grain size was measured on the dried sediments using a Malvern Mastersize analyser after shaking the samples overnight in a 1% Calgon solution to disaggregate them. Oxygen concentrations were determined using the Winkler titration technique. DIC was measured using an infrared analyser to detect CO2 released from the sample after acidifying with 10 % H3PO4. Total alkalinity was determined by Gran titration. Cations were measured by inductively coupled plasma optical emission spectrometry and by inductively coupled plasma mass spectrometry. Anions were measured by ion exchange chromatography with 9 mmol L-1 NaCO3 as the eluent. The carbon isotopic composition of the DIC (δ13CDIC) was determined using a multiflow preparation system coupled to an continuous flow mass spectrometer. Total alkalinity was determined by titration against 0.0005 mol L-1 HCl using a mixture of methyl red and methylene blue as an indicator. Total dissolved sulphide concentrations (H2S + HS- + S2-) were determined using the diamine complexation method. Concentrations of methane were determined by gas chromatography. The data in the table is the format Dx/Dx (day relative to injection). D-6/-7: 10/11 May 2012 D13/14: 30/31 May 2012 D34/D35: 20/21 June 2012 D41/D42: 27/28 June 2012 D53/D54: 9 July/10 July 2012 D126/D127: 18/20 September 2012 D356/D357/D358: 8/9/10 May 2013

gmd:MD_Metadata

File identifier

0a6b0b4d-65a2-2bdb-e054-002128a47908   XML

Metadata language

English English

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dataset Dataset

Date stamp

2020-07-10

Metadata standard name

UK GEMINI

Metadata standard version

2.3

Dataset URI

http://data.bgs.ac.uk/id/dataHolding/13606455