# Bulk sediment nitrogen isotopes from the northern Peru Margin over the last 25 kyr
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#               World Data Service for Paleoclimatology, Boulder
#                                   and
#                      NOAA Paleoclimatology Program
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# Template Version 3.0
# Encoding: UTF-8
# NOTE: Please cite original publication, online resource and date accessed when using this data.
# If there is no publication information, please cite Investigator, title, online resource and date accessed.
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# Description/Documentation lines begin with #
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# Online_Resource: https://www.ncdc.noaa.gov/paleo/study/25430
#      Description: NOAA Landing Page
# Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/bova2018/bova2018-cdh41-14c.txt
#      Description: NOAA location of the template
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# Archive: Paleoceanography
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# Dataset_DOI:
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# Parameter_Keywords: nitrogen isotopes, carbon isotopes
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# Contribution_Date
#    Date: 2018-10-15
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# File_Last_Modified_Date
#    Date: 2018-10-15
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# Title
#    Study_Name: Bulk sediment nitrogen isotopes from the northern Peru Margin over the last 25 kyr
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# Investigators
#      Investigators: Bova, Samantha C.; Herbert, Timothy D.; Altabet, Mark A.
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# Description_Notes_and_Keywords
#        Description: 
#         Provided Keywords: deglaciation, upwelling, Younger Dryas
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# Publication
# Authors: Bova, S.C., T.D. Herbert, and M.A. Altabet
# Published_Date_or_Year: 2018
# Published_Title: Ventilation of northern and southern sources of aged carbon in the eastern equatorial Pacific during the Younger Dryas rise in atmospheric CO2
# Journal_Name: Paleoceanography and Paleoclimatology
# Volume: in press
# Edition: 
# Issue: 
# Pages: 
# Report_Number: 
# DOI: 
# Online_Resource: 
# Full_Citation: 
# Abstract: Atmospheric carbon dioxide (CO2) levels rose by ~90 ppmv during the last deglaciation, but the source of this carbon remains unknown. One popular hypothesis suggests carbon accumulated in the deep Southern Ocean, becoming increasingly radiocarbon (14C)-depleted during the last glacial period, and was released into Antarctic Intermediate Water (AAIW) and, subsequently, the atmosphere during deglaciation. Detection of extremely 14C-deplete carbon in the intermediate-depth tropical oceans during periods of atmospheric CO2 rise was initially considered the "smoking gun" for the hypothesis, but attempts to reproduce the anomalies closer to the Southern Ocean source have largely failed. Here, we present new 14C records from four cores recovered at intermediate depths in the eastern equatorial Pacific (EEP). In the context of additional geochemical records, including benthic foraminiferal stable isotopes and sedimentary nitrogen isotopes, we demonstrate that the extreme 14C anomalies observed during the last deglaciation do not reflect the radiocarbon content of AAIW. We show that, although AAIW likely transported modestly 14C-deplete carbon to the EEP subsurface, the extreme 14C signatures might reflect a distinct source of aged carbon arriving from the north, suggesting the North Pacific helped transport deep ocean carbon to the atmosphere during the last deglaciation. In the EEP, additional local hydrothermal inputs of 14C-free carbon near the Galapagos Islands magnified the already low-14C signatures. Finally, regardless of arrival route (North/South Pacific or hydrothermal), 14C-deplete carbon was released from the EEP subsurface during a late deglacial pulse of renewed upwelling, likely contributing to the Younger Dryas rise in atmospheric CO2.
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# Funding_Agency
#    Funding_Agency_Name: National Science Foundation
#    Grant: OCE-1003387
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# Site_Information
# Site_Name: KNR195-5 CDH41
# Location: Eastern Pacific Ocean
# Country: 
# Northernmost_Latitude: -1.265667
# Southernmost_Latitude: -1.265667
# Easternmost_Longitude: -89.698
# Westernmost_Longitude: -89.698
# Elevation: -595
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# Data_Collection
#   Collection_Name: CDH41 14C Bova2018
#   First_Year: 10346
#   Last_Year: 28238
#   Time_Unit: cal yr BP
#   Core_Length: 26.87
#   Notes: 
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# Chronology_Information 
# Chronology: 
# 
# Labcode 	
# depth_top	
# depth_bottom	
# mat.dated 	
# 14C.raw	
# 14C.raw_err 	
# datemeth  	
# reservoir age	
# calib.14C  	
# calib.14C_97.5% confidence interval lower bound	
# calib.14C_97.5% confidence interval upper bound	
# calib_method 	
# calib_curve	
# rejected 	
# 
# Labcode	depth_top	depth_bottom	mat.dated	14C.raw	14C.raw_err	datemeth	reservoir age	calib.14C  	calib.14C_97.5% confidence interval lower bound	calib.14C_97.5% confidence interval upper bound	calib_method            	calib_curve	rejected	
# OS-99072   	0.5	0	Globigerinoides ruber	9580	50	14C AMS	393	10346	10249	10491	Bchron	intcal13	no	
# OS-113942  	4.75	4.25	Globigerinoides ruber	10500	45	14C AMS	505	11460	11285	11693	Bchron	intcal13	no	
# OS-102469  	10.25	9.75	Globigerinoides ruber	12150	100	14C AMS	1119	12901	12739	13070	Bchron	intcal13	no	
# OS-102711  	15.5	15	Globigerinoides ruber	12550	45	14C AMS	1285	13117	13066	13215	Bchron	intcal13	no	
# OS-113944  	17.5	17	Globigerinoides ruber	12750	55	14C AMS	1367	13222	13119	13328	Bchron	intcal13	no	
# OS-102466  	20.5	20	Globigerinoides ruber	11850	65	14C AMS	995	12737	12690	12869	Bchron	intcal13	yes	
# OS-113946  	25.5	25	Globigerinoides ruber	13800	55	14C AMS	1412	14425	14193	14744	Bchron	intcal13	no	
# OS-99073   	30.25	29.75	Globigerinoides ruber	14350	60	14C AMS	1283	15670	15427	15837	Bchron	intcal13	yes	
# OS-113948  	35.5	35	Globigerinoides ruber	13950	60	14C AMS	1378	14917	14569	15108	Bchron	intcal13	no	
# OS-102713  	40.5	40	Globigerinoides ruber	12700	50	14C AMS	1322	13218	13121	13306	Bchron	intcal13	yes	
# OS-113950  	47.5	47	Globigerinoides ruber	14300	70	14C AMS	1304	15546	15317	15754	Bchron	intcal13	no	
# OS-102715  	55.5	55	Globigerinoides ruber	14450	60	14C AMS	1268	15839	15678	16008	Bchron	intcal13	no	
# OS-99074   	70.25	69.75	Globigerinoides ruber	15650	80	14C AMS	1775	16812	16557	17041	Bchron	intcal13	no	
# OS-102717  	90.25	89.75	Globigerinoides ruber	18150	90	14C AMS	2058	19416	19187	19610	Bchron	intcal13	no	
# OS-119357  	100.5	100	Globigerinoides ruber	18750	100	14C AMS	1994	20216	19997	20461	Bchron	intcal13	no	
# OS-99075   	115.5	115	Globigerinoides ruber	19700	140	14C AMS	1855	21607	21206	21915	Bchron	intcal13	no	
# OS-102719  	135.25	134.75	Globigerinoides ruber	20400	120	14C AMS	1953	22320	22007	22500	Bchron	intcal13	no	
# OS-99076   	170.25	169.75	Globigerinoides ruber	20600	120	14C AMS	1982	22479	22277	22747	Bchron	intcal13	no	
# OS-119358  	215.5	215	Globigerinoides ruber	14200	60	14C AMS	2000	14089	13904	14237	Bchron	intcal13	yes	
# OS-109334  	235.5	235	Globigerinoides ruber	17950	70	14C AMS	2078	19129	13968	19338	Bchron	intcal13	yes	
# OS-119359  	255.5	255	Globigerinoides ruber	24700	210	14C AMS	2000	27020	26514	27382	Bchron	intcal13	no	
# OS-109363  	275.5	275	Globigerinoides ruber	24000	120	14C AMS	2000	26193	26005	26466	Bchron	intcal13	no	
# OS-109458  	290.5	290	Globigerinoides ruber	27200	190	14C AMS	2000	29242	28849	29658	Bchron	intcal13	no	
# OS-119360  	310.5	310	Globigerinoides ruber	26200	260	14C AMS	2000	28238	27810	28709	Bchron	intcal13	no	
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# Variables
# Data variables follow that are preceded by "##" in columns one and two.
# Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data)
## depth_cm	depth,,,centimeter,,,,,N,
## age_calyr	age,,,calendar year before present,,,,,N,
## benthic_14Cage	age,benthic foraminifer,,radiocarbon year before present,,paleoceanography,,accelerator mass spectrometry,N,
## benthic_14Cage_sd	Delta 14C,benthic foraminifer,one standard deviation,radiocarbon year,,,,,N,
## Labcode	sample identification,,,,,,,,C,sample identification used by 14C laboratory 
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# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing_Values: NA
depth_cm	age_calyr	benthic_14Cage	benthic_14Cage_sd	labcode	
0.25	10373	9560	50	OS-101662  	
4.5	11469	11900	50	OS-113941  	
10	12819.5	14900	70	OS-102464  	
15.25	13108.5	15300	56	OS-102712  	
17.25	13261	14600	70	OS-113943  	
20.25	13680.5	14150	70	OS-102467  	
25.25	14313	15500	75	OS-113945  	
30	14647	15400	95	OS-101663  	
35.25	14929.5	16500	80	OS-113947  	
40.25	15219	14950	60	OS-102714  	
47.25	15559	16700	80	OS-113949  	
55.25	15866	17700	90	OS-102716  	
70	16837	18850	150	OS-101664  	
90	19395	21000	130	OS-102718  	
100.25	20213	22300	160	OS-119356  	
115	21532.5	21600.00	210	OS-101665  	
135	22220.5	23100.00	220	OS-102413  	
170	22533.5	23500.00	240	OS-101667  	
215	24030	24200.00	350	OS-118822  	
235	25035	25500.00	140	OS-109457  	
255	26165	29800.00	710	OS-118823  	
275	26398.5	28100.00	180	OS-109287  	
290	27508.5	27000.00	140	OS-109362  	
310	28301	28100.00	320	OS-119362