Citation:

PANGAEA.980873 (dataset in review)

Name: XRF data from a temperate fjord in Alaska over the last 2,000 years
License: https://creativecommons.org/licenses/by/4.0/
Keywords: bromine; chemical analysis; chlorine; ocean processes; unconsolidated deposits; X-ray fluorescence

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Abstract:

Scanning X-ray fluorometry (XRF) data were collected from the split surfaces of cores EW0408-32MC, -32TC, and -33JC (see Addison et al., 2013; doi:10.1002/jgrc.20243). Using the composite depth scale and alignment of the XRF data from the three cores, a continuous XRF data splice was generated. This splice uses the following depth horizons: 0.0-0.27 m bsf in EW0408-32MC; 0.272 – 0.65 m bsf in -33TC; and >0.65 m bsf in -33JC. This data release specifically focuses on the scanning XRF datasets for bromine (Br) and chlorine (Cl), as the Br/Cl ratio has been shown to reflect variations in primary productivity (see Addison et al., 2013; doi:10.1002/jgrc.20243 ). In addition to the raw counts per second units for Br and Cl, statistical calculations are also included: the geometric mean of all X-ray counts, which is in turn used to calculate the centered natural-log-ratio (clr) transformations of both Br and Cl. The resulting clr Br / clr Cl ratio is calculated, and a two-part linear background is removed from the dataset to correct for sediment compaction. The detrended clr Br / clr Cl data are presented in their native format, as well as being normalized to Z-scores; raw and 10-yr multi-pass smoothed data are included in this data release. A multi-decadal (40-yr) variance calculation is also included.

Keyword(s):

bromine; chemical analysis; chlorine; ocean processes; unconsolidated deposits; X-ray fluorescence

References:

Addison, Jason A; Finney, Bruce P; Jaeger, John M; Stoner, Joseph S; Norris, Richard D; Hangsterfer, Alexandra (2013): Integrating satellite observations and modern climate measurements with the recent sedimentary record: An example from Southeast Alaska. Journal of Geophysical Research: Oceans, 118(7), 3444-3461, https://doi.org/10.1002/jgrc.20243

Coverage:

Latitude: 57.162000 * Longitude: -135.357000

Date/Time Start: 2004-08-29T00:00:00 * Date/Time End: 2004-08-31T00:00:00

Minimum Elevation: -146.0 m * Maximum Elevation: -146.0 m

Event(s):

EW0408-32MC2 * Latitude: 57.162000 * Longitude: -135.357000 * Date/Time: 2004-08-29T00:00:00 * Elevation: -146.0 m * Recovery: 0.38 m * Location: Gulf of Alaska * Campaign: * Basis: Maurice Ewing * Method/Device: MultiCorer (MUC)

EW0408-33JC * Latitude: 57.162000 * Longitude: -135.357000 * Date/Time: 2004-08-31T00:00:00 * Elevation: -146.0 m * Recovery: 18.19 m * Location: Gulf of Alaska * Campaign: * Basis: Maurice Ewing * Method/Device: Jumbo Piston Core (JPC)

EW0408-33TC * Latitude: 57.162000 * Longitude: -135.357000 * Date/Time: 2004-08-31T00:00:00 * Elevation: -146.0 m * Recovery: 0.712 m * Location: Gulf of Alaska * Campaign: * Basis: Maurice Ewing * Method/Device: Trigger corer (TC)

Parameter(s):

#	Name	Short Name	Unit	Principal Investigator	Method/Device	Comment
1	Event label	Event		Addison, Jason A
2	Latitude of event	Latitude		Addison, Jason A
3	Longitude of event	Longitude		Addison, Jason A
4	Date/Time of event	Date/Time		Addison, Jason A
5	Core	Core		Addison, Jason A
6	Depth, composite	Depth comp	mcd	Addison, Jason A
7	Age	Age	a AD/CE	Addison, Jason A
8	AGE	Age	ka BP	Addison, Jason A		Geocode
9	Bromine	Br	cps	Addison, Jason A	X-ray fluorescence core scanner (XRF), Avaatech	Raw
10	Chlorine	Cl	cps	Addison, Jason A	X-ray fluorescence core scanner (XRF), Avaatech	Raw
11	Geometric mean	Geom mean		Addison, Jason A	X-ray fluorescence core scanner (XRF), Avaatech	Geometric mean of all measured cps measurements analyzed by scanning XRF. See Addison et al. (2013, doi:10.1002/jgrc.2024) for more details.
12	Bromine (centered log ratio)	Br (CLR)		Addison, Jason A	Derived from X-ray fluorescence core scanner (XRF), Avaatech	Calculated by dividing column "Br [cps]" by corresponding value in "Geometric mean", and then applying a natural logarithm transformation.
13	Chlorine (centered log ratio)	Cl (CLR)		Addison, Jason A	Derived from X-ray fluorescence core scanner (XRF), Avaatech	Calculated by dividing column "Cl [cps]" by corresponding value in "Geometric mean", and then applying a natural logarithm transformation.
14	Bromine/Chlorine ratio (centered log ratio)	Br/Cl (CLR)		Addison, Jason A	Derived from X-ray fluorescence core scanner (XRF), Avaatech	Centered-log-ratio-transformed Br/Cl ratio.
15	Two-part linear regression	TP LRE		Addison, Jason A	Calculated	Applied to the Br/Cl (CLR). Regression #1 extends from 0.2 to 69.0 cm bsf, and regression #2 ranges between 69.2 to 553.0 cm bsf. See abstract for additional details.
16	Bromine/Chlorine ratio (centered log ratio)	Br/Cl (CLR)		Addison, Jason A	Detrended	Resulting detrended Br/Cl (CLR) after removing background linear trends calculated in "Two-part linear regression"
17	Bromine/Chlorine ratio (centered log ratio)	Br/Cl (CLR)		Addison, Jason A	Calculated	Multi-pass moving average 10 a smoothed curve applied to "Br/Cl (CLR), detrended".
18	Z-score	Z-score		Addison, Jason A	Calculated	Z-scores calculated from "Br/Cl (CLR), detrended" where each value is standardized to a population zero mean and unit variation.
19	Average	avg		Addison, Jason A	Smoothed	Multi-pass moving average 10-yr smoothed curve applied to "Z-score".
20	Variance	Var		Addison, Jason A	Calculated	Multi-decadal (40yr) variance of the "Z-score".

License:

Creative Commons Attribution 4.0 International (CC-BY-4.0) (License comes into effect after moratorium ends)

Status:

Curation Level: Enhanced curation (CurationLevelC)

Size:

39731 data points

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