Lead (Pb) isotopic ratios in lake water, river water, groundwater, and TSP samples collected in and around Lake Tahoe from 2006 to 2016

Website: https://www.bco-dmo.org/dataset/856001
Data Type: Cruise Results, Other Field Results
Version: 1
Version Date: 2021-07-16

Project
» Atmospheric Deposition Impacts on Marine Ecosystems (ADIMA)
ContributorsAffiliationRole
Paytan, AdinaUniversity of California-Santa Cruz (UCSC)Principal Investigator
Chien, Chia-TeUniversity of California-Santa Cruz (UCSC)Student
Rauch, ShannonWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Abstract
This dataset reports Lead (Pb) isotopic ratios in lake water, river water, groundwater, and TSP samples collected in and around Lake Tahoe from 2006 to 2016. Total suspended particle (TSP) samples were collected weekly using a Graseby Andersen TSP High Volume Sampler located near the lake at the UC Davis Field Station. Water depth profiles were collected seven times at different seasons between the Spring of 2013 and Summer 2016 using Van Dorn bottles. ). Groundwater samples were obtained from two wells at the Lake Tahoe fire station and three wells at the Hatchery. River water samples were collected from Third Creek, Trout Creek, Upper Truckee River, Ward Creek, Incline Creek, Blackwood Creek and General Creek.


Coverage

Spatial Extent: Lat:39.09231 Lon:-120.00275
Temporal Extent: 2006-01-03 - 2016-07-22

Methods & Sampling

Total suspended particle (TSP) samples were collected between 2005 and 2010. Weekly integrated samples were collected on acid washed quartz fiber filters (10"x8", Whatman®) using a Graseby Andersen TSP High Volume Sampler. Between November 2005 and May 2007, the sampler was located near the lake at the UC Davis Field Station (Hatchery) away from any local source of disturbance. After May 2007, the sampler was relocated about 300m south to reduce local impacts due to remodeling at the Hatchery. The TSP sampler was placed 3.2m above the ground and protected by trees from direct road dust inputs. TSP samples were collected at an airflow rate of 85m3 h−1. All filters were kept frozen until further analyses.

Water depth profile samples from Lake Tahoe were collected seven times at different seasons between the Spring of 2013 and Summer 2016. Van Dorn bottles (Wildco Beta Plus acrylic 2.2 L, with no metal parts that touch the sample) were used for water collection at depths of 50, 100, 150, 200, 250, 300, 350, 400, and 450m and a one-liter HDPE bottle attached to a 2.5m long plastic rod was used to collect surface water samples. Samples were collected at the Mid-lake Tahoe Profile (MLTP) station (39.09231° N; 120.00275° W). From each depth, one liter of water was dispensed into an acid-washed sample rinsed LDPE bottle for trace metals and Pb isotope analyses as described in Chien et al. (2017). Groundwater samples were obtained from two wells at the Lake Tahoe fire station and three wells at the Hatchery, and river water samples were collected from Third Creek, Trout Creek, Upper Truckee River, Ward Creek, Incline Creek, Blackwood Creek and General Creek. All water samples were filtered with acid washed 0.45 μm filters (SupaPore) before nutrient, trace metal and Pb isotope analyses. Samples for trace metal and Pb isotopes analyses were acidified to pH < 2 with concentrated double distilled nitric acid. MilliQ water blanks were also collected and analyzed similarly.

In order to separate Pb from the different sample matrices, 500 mL from each water sample and the digested TSP samples were dried down and re-dissolved in 100 μL of concentrated HBr (Optima grade, Fisher Scientific) three times. Pb was separated using AG1-X8 resin. Briefly, the matrix of the samples was eluted with 1 N HBr and the Pb fraction was eluted by 6 N double distilled HNO3, this eluent was then dried down and brought up with 2% HNO3 to ~2 ppb for analyses. Pb separation and trace metal pretreatments were done in the clean room in the Keck lab of UCSC. To determine Pb isotopic composition, analyses were carried out on a Thermo Element XR HR-ICP-MS in the Marine Analytical Laboratory at UC Santa Cruz following the method developed by (Zurbrick et al., 2013). 204Pb, 206Pb, 207Pb and 208Pb were analyzed and 200Hg and 202Hg were also monitored for isobaric interference correction on 204Pb. Pb isotopes in the samples were corrected by bracketing to NIST SRM-981 values; NIST SRM-981 was analyzed between every five samples. Typically, a 2 ppb Pb solution resulted in a signal of about 4x10^6 counts per second on 208Pb, external precision (2σ) for 206Pb/204Pb, 206Pb/207Pb and 208Pb/207Pb are 5.7‰, 3.7‰ and 2.2‰, respectively (based on 33 NIST SRM-981 analyses).


Data Processing Description

BCO-DMO Processing:
- changed date format to YYYY-MM-DD;
- renamed fields to comply with BCO-DMO naming conventions.


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Data Files

File
lake_tahoe_pb.csv
(Comma Separated Values (.csv), 6.81 KB)
MD5:45c591b0c6c3005922acb0c6da60a797
Primary data file for dataset ID 856001

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Related Publications

Buck, C. S., Landing, W. M., Resing, J. A., & Lebon, G. T. (2006). Aerosol iron and aluminum solubility in the northwest Pacific Ocean: Results from the 2002 IOC cruise. Geochemistry, Geophysics, Geosystems, 7(4), n/a–n/a. doi:10.1029/2005gc000977 https://doi.org/10.1029/2005GC000977
General
Chien, C.-T., Allen, B., Dimova, N. T., Yang, J., Reuter, J., Schladow, G., & Paytan, A. (2019). Evaluation of atmospheric dry deposition as a source of nutrients and trace metals to Lake Tahoe. Chemical Geology, 511, 178–189. doi:10.1016/j.chemgeo.2019.02.005
Results
Chien, C.-T., Ho, T.-Y., Sanborn, M. E., Yin, Q.-Z., & Paytan, A. (2017). Lead concentrations and isotopic compositions in the Western Philippine Sea. Marine Chemistry, 189, 10–16. doi:10.1016/j.marchem.2016.12.007
Methods
Zurbrick, C. M., Gallon, C., & Flegal, A. R. (2013). A new method for stable lead isotope extraction from seawater. Analytica Chimica Acta, 800, 29–35. doi:10.1016/j.aca.2013.09.002
Methods

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Parameters

ParameterDescriptionUnits
Typesample type (TSP = Total Suspended Particle) unitless
Datedate of collection; for TSP the date is the beginning date of collection; format: YYYY-MM-DD unitless
Locationlocation unitless
Depthwater depth meters (m)
Pb206_Pb204206Pb to 204Pb ratio unitless
Pb206_Pb204_stdevOne standard deviation of 206Pb to 204Pb ratios unitless
Pb206_Pb207206Pb to 207Pb ratio unitless
Pb206_Pb207_stdevOne standard deviation of 206Pb to 207Pb ratios unitless
Pb208_Pb207208Pb to 207Pb ratio unitless
Pb208_Pb207_stdevOne standard deviation of 208Pb to 207Pb ratios unitless


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Instruments

Dataset-specific Instrument Name
Thermo Element XR HR-ICP-MS
Generic Instrument Name
Inductively Coupled Plasma Mass Spectrometer
Dataset-specific Description
Thermo Element XR high-resolution inductively coupled plasma mass spectrometer (HR-ICP-MS)
Generic Instrument Description
An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer.

Dataset-specific Instrument Name
Graseby Andersen TSP High Volume Sampler
Generic Instrument Name
Aerosol Sampler
Generic Instrument Description
A device that collects a sample of aerosol (dry particles or liquid droplets) from the atmosphere.

Dataset-specific Instrument Name
Van Dorn bottles
Generic Instrument Name
Van Dorn water sampler
Generic Instrument Description
A free-flushing water sample bottle comprising a cylinder (polycarbonate, acrylic or PVC) with a stopper at each end. The bottle is closed by means of a messenger from the surface releasing the tension on a latex band and thus pulling the two stoppers firmly into place. A thermometer can be mounted inside the bottle. One or more bottles can be lowered on a line to allow sampling at a single or multiple depth levels. Van Dorn samplers are suitable for for physical (temperature), chemical and biological sampling in shallow to very deep water. Bottles are typically lowered vertically through the water column although a horizontal version is available for sampling near the seabed or at thermoclines or chemoclines. Because of the lack of metal parts the bottles are suitable for trace metal sampling, although the blue polyurethane seal used in the Alpha version may leach mercury. The Beta version uses white ASA plastic seals that do not leach mercury but are less durable.


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Deployments

Lake_Tahoe_Paytan

Website
Platform
R/V John Le Conte
Description
Cruise identifiers: 442, 450, 453, 468, 471, 474, 481.


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Project Information

Atmospheric Deposition Impacts on Marine Ecosystems (ADIMA)


Coverage: Gulf of Aqaba, Atlantic Ocean (Bermuda Time Series Station), Monterey Bay


Chemical components delivered to the surface ocean through atmospheric deposition influence ocean productivity and ecosystem structure thus are tightly related to the global carbon cycle and climate. Accordingly, the major aim of this project is to quantitatively estimate the variable impact of aerosols on marine phytoplankton and to determine the specific effects on various taxa. Such data could in the future be used to better understand the global impact of aerosols on the oceanic ecosystem. To accomplish this goal the PI will monitor aerosol dry deposition fluxes, determine aerosol sources, obtain the chemical composition and solubility of aerosols, and evaluate the contribution of aerosols to nutrient and trace metal budgets of seawater at two oceanographically different sites (Bermuda and Monterey Bay) representing open ocean and coastal setting. The effects of the different aerosol "types" (defined by source and chemical characteristics) on specific phytoplankton taxa will also be evaluated using pure culture and natural samples bioassays. This project is particularly important in light of the role atmospheric deposition can resume in oligotrophic and coastal settings and the predicted future global conditions of increased aridity and urbanization and associated changes in dust fluxes and composition.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)

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