Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS Chlorophyll (mg m -3 ) Among the objectives of KEOPS - Identification of the mechanisms of natural.

Slides:

Advertisements

Similar presentations

Particulate organic matter and ballast fluxes measured using Time-Series and Settling Velocity sediment traps in the northwestern Mediterranean Sea lead.

Advertisements

Dissolution of calcite in sediments -- metabolic dissolution.

Mantle geochemistry: How geochemists see the deep Earth Don DePaolo/Stan Hart CIDER - KITP Summer School Lecture #1, July 2004.

AMANDES research project PI: C. Jeandel-P.Seyler 4 french joint labs IRD/CNRS/Univ. Brasilian cooperations: UnB, UFF, USP (IO, IPEN) Processo CNPq n° /

Nitrogen Isotopes & the biological pump11/8/12 Lecture outline: 1)the nitrogen cycle  15 N overview 3)ocean applications 4)the sedimentary record A.

RADINUCLIDES IN THE OCEANS: a tool for understanding the ecosystems functioning Roberta Delfanti ENEA – Marine Environment Research Centre, La Spezia IAEA.

Lecture 2 - Major Ions in Sea Water Why do we care about the major ions? What is the composition of seawater? What defines Major Ions? What are their concentrations?

Uranium and Thorium Distributions in the Sediments Collected from the Western South Okinawa Trough and the Northern South China Sea Chun-Yen Wang, Li-Wen.

Abstract As part of the VERTIGO project (VERtical Transport In the Global Ocean) we used Thorium-234 ( 234 Th) as a natural proxy for particle export.

The Earth II: The Core; Mantle Reservoirs Lecture 46.

UK GEOTRACES: Characterizing nitrate isotopes in South Atlantic water masses (40°S). UK GEOTRACES: Characterizing nitrate isotopes in South Atlantic water.

GEOF236 CHEMICAL OCEANOGRAPHY (HØST 2012) Christoph Heinze University of Bergen, Geophysical Institute and Bjerknes Centre for Climate Research Prof. in.

EPOCA Kick-off Meeting June 2008: Nice Theme 1Ocean chemistry and biogeography What is the past and recent variability of ocean carbonate chemistry (including.

Nutrient dynamics in the deep blue sea – David M. Karl

The Biogeochemical Cycle Of Barium Caroline Schmidt.

OCN520 Fall 2009 Mid-Term #2 Review Since Mid-Term #1 Ocean Carbonate Distributions Ocean Acidification Stable Isotopes Radioactive Isotopes Nutrients.

Weathering Sources in the Kaoping River Catchment, Southwestern Taiwan: Insights From Major and Trace Elements, Sr Isotopes and Rare Earth Elements C.-F.

Systematics of Neodymium Isotopes

Economic and environmental considerations

Principles of Mass Balance

Lecture 3 Trace Metals in Seawater What are trace elements? Why are they important? Principal of Oceanographic Consistency. Profiles shapes as clues for.

Carbonates Madelon van den Hooven

Iron isotope constraints on Fe cycling and mass balance in oxygenated Earth oceans Brian L. Beard, Clark M. Johnson, Karen L. Von Damm, Rebecca L. Poulson.

Iron Isotopes 11/15/12 Lecture outline: the basics abiotic and biotic

Re-Os & U-Th-Pb Isotope Geochemistry

Paper Number OS 26A-06 At both sites, the majority of the vertical flux attenuation of components such as carbon occurred with the mesopelagic “Twilight.

Using geochemical proxies to trace sediment sources Karin Block & Annika Johansson Columbia University.

BNL INL Lateral Transport of Dissolved and Particulate TEIs at Ocean Margins K2-NW Pacific % Transmission Along Line W 228 Ra.

Dissolved iron distributions and Fe-limitation C. Guieu & S. Bonnet Laboratoire d’océanographie de Villefranche S. Blain Laboratoire d’océanographie et.

Reconsidérer les flux continent-océan Catherine Jeandel& Eric Oelkers (2014) CNRS, LEGOS, Observatoire Midi-Pyrénées, Toulouse University CNRS, GET, Observatoire.

Using Heavy Isotopes in Marine Barite to Characterize Ocean Chemistry Changes Andrea M. Erhardt Stanford University University of California - Santa Cruz.

Inputs to shelf seas- an overview Materials are introduced into coastal and shelf seas primarily through: rivers, atmosphere, groundwaters, ice processes.

Marine Geochemistry 2 Reference: Schulz and Zabel Marine Geochemistry Springer, New York pp. ISBN X.

T, light/UV, mixing, Fe, Si, …. Climate change C export CO 2, CH 4, COV CH 3 I DMS DMSe N2ON2O aérosols Structure of the phytolankton community CHX General.

Iron and Biogeochemical Cycles

The distribution of dissolved zinc in the South Atlantic as part of the UK GEOTRACES Programme UK GEOTRACES N. Wyatt 1, A. Milne 1, M. Woodward 2 G. Henderson.

Lead isotopes in South Atlantic seawater from the UK GEOTRACES transect along 40°S Maxence Paul Mark Rehkämper, Tina van de Flierdt, Dominik Weiss.

LONGITUDINAL VARIABILITY OF EXPORT FLUXES OF PARTICULATE MATTER BASED ON 234 TH BUDGETS IN THE ATLANTIC SECTOR OF THE SOUTHERN OCEAN ALONG 40S [GEOTRACES.

Fe, Zn, and Cd stable isotopes from the eastern tropical South Pacific from GEOTRACES cruise GP16 – Methods and data Josh Helgoe, Emily Townsend, & Seth.

Sediment trap data. Constraining the seasonal particle flux in the eastern North Atlantic with Thorium isotopes M. Roy-Barman (1), R. El Hayek (1), I.

CO 2 and Climate Change. Lisiecki & Raymo,

N cycling in the world’s oceans

Tracking the fate of carbon in the ocean using thorium-234 Ken Buesseler Dept. of Marine Chemistry and Geochemistry Woods Hole Oceanographic Institution.

Kaijun Su a, Jinzhou Du a, *, Mark Baskaran b and Jing Zhang a State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai.

Preliminary Results of the CASCADE Cruise (Gulf of Lions) R/V l’Atalante, March 2011 CEFREM, ICM-CSIC, UB, UPM, IFREMER, LA, HCMR, LOV, LMGEM,

Iron : Chemistry, sources and sinks..  Iron is the limiting factor in the surface water of S.O.  HNLC conditions « Iron hypothesis » (Martin et al.

Marine Ecosystem Simulations in the Community Climate System Model

Δ 56 Fe – Motivation GA10 Samples & Planned Work We have deep water profiles from the trace metal casts For JC068 we have stations 8, 11, 12, 13, 16, 18.

Interpreting the sedimentary record

Physical and Chemical characterization of the aerosol during the cruise Guieu/Losno/Bonnet/Blain/Gaudichet 1) Scientific objectives:  Determine the particles.

210 Po Enrichment Relative to 210 Pb in the Planktons Collected from the Northern South China Sea and the Luzon Strait P. Wang and Y. Chung Institute of.

New directions in limnology and oceangraphy using cosmogenic radionuclides Erik Brown Large Lakes Observatory Department of Geological Sciences University.

32 S 96% 34 S 4% Sulfur isotope systematics Controls on the  34 S of marine sulfide minerals geologic S isotope cycle - implications for C and O cycles.

Radiometric dating and sediment accumulation rates Dating principles – covered in Isotope Geochemistry (Faure) Two radiocarbon approaches: Average slopes.

Sulfate reduction idealized stoichiometry pathways and substrates case studies Cape Lookout Bight – extreme SR Southwest African margin – subtle SR Microbial.

U-series Nuclides & Particles U.S. GEOTRACES Atlantic Implementation Workshop Sept Woods Hole Oceanographic Institution Bob Anderson.

Sediment Geochemistry Split the lectures about evenly; both attend all. Work will include: - Reading papers and participating in classroom.

Biogenic Silica in Marine Sediments Inputs and Outputs Distribution Burial Efficiency Mechanisms of dissolution & preservation.

Proposed German RV Meteor cruise to the Central Atlantic Ocean Barbados – Las Palmas currently scheduled for April 9 – May 9, 2009.

Dr. Claudia Benitez-Nelson University of South Carolina Radionuclides in Ocean: A General Introduction to Marine Radioactivity.

Theme 1: Biological uptake and trace element bioavailability

Transport and Reaction: An Overview

RADINUCLIDES IN THE OCEANS:

Fe and Mn in sediments Their use as electron acceptors for Corg oxidation Mn cycling within the sediment column Fe cycling within the sediment column.

222Rn, oxygen, nutrients (nitrate, ammonia, phosphate)

Frontiers in ocean chemistry: Forcing and tracing climate processes

Stable Isotope Analyses of Bioactive Trace Metals

Particulate and Dissolved 210Po and 210Pb in Water Columns from the

Iron and Biogeochemical Cycles

210Pb and Mass Flux Imbalance Between the Settling Particulates and

Presentation transcript:

Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS Chlorophyll (mg m -3 ) Among the objectives of KEOPS - Identification of the mechanisms of natural iron fertilization on the Kerguelen Plateau - Processes explaining this fertilization - Flux studies in contrasting environments Contribution of the geochemical tracers ? (LEGOS, LSCE, CEREGE, ANCH, IPGP)

Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS Origin of the iron enrichment ?  Contact with the margin when deep waters circulate around the plateau (release from the shelf sediment, dissolution of particles)  Remineralization of sinking biogenic material after a massive bloom What is the major mechanism of the upward transfer of iron from deep waters to the surface layer?  tidal currents + bottom topography  internal tides transfering deep water to the surface. Questions that will be addressed using the geochemical tracers What kind of tracers ? Coupled with the physics…

Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS Radium isotopes : 226 Ra : 1602 a ; 228 Ra : 5.75 a tracer of water masses : - signature of the water masses that were in contact with the shelf input from the sediments : tracer of iron enrichment - information on the transit time of the water masses since they detached from the shelves 226 Ra is expected to behave conservatively but not 228 Ra … we need to interact with physicists tracer of particles : 226 Ra/ 228 Ra ratio of particles compared with that of seawater : origin of particles that form in the water column (= flux studies)

Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS The isotopes  Kerguelen Archipelago = intraplate islands  Geological material outcropping characterised by a specific elemental composition and isotopic ratios. - Rare Earth Element (REE) patterns: completely OPPOSITE from the seawater REE pattern - ε Nd values range between –2 to +2 (seawater around –8) - same for lead isotopic composition The Elemental Composition  Kerguelen fields = different from that of the marine sediments (eg: richer in Ti, in Fe, poorer in Ba)  Analysis of sediments and interstitial water content will contribute to characterize the iron content and also to identify the source of this material. REE patterns, trace elements, Nd and Pb isotopes: Source tracers

Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS Fe isotopes (F. Lacan’s project)  56 Fe ‰ = [ ( 56 Fe/ 54 Fe ECHANTILLON ) / ( 56 Fe/ 54 Fe REFERENCE ) -1 ] x 10 3 MC/ICPMS: precision today = 0.05‰ with 20 ng of Fe IN VITRO studies (Butler et al and Beard et al, 2003) :  Bacterial reduction could yield an isotope deviation of -1.3‰  FeS precipitation : -0.3 ‰  This allows us to assume that the dissolved iron released by the margins have distinct iron signatures compared with the continental one.  Hypothesis verified by recent works shown in Portland (OS 2004) on the Californian margin (Severmann et al, 2004). Hypothesis: FeOx reduction on the continental margins could yield an isotopic fractionation KEOPS: To determine Fe signatures in the water and particles before and after the contact + in the sediment cores :  Sediment and interstitial waters: Fe fractionation factor  Iron fluxes between the water masses and the sediments  To follow the evolution of this signature when leaving the margin

Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS 231 Pa / 230 Th ratios: - both decay products of soluble and conservative U (ie. 235 U and 234 U) - produced at a fixed known rate in the ocean and sensitive to scavenging Th (  =50 years) more reactive than 231 Pa (  = 200 years) trace more rapid and recent processes - no efficient subtraction or ventilation regular increase of activities with depth - when distributions of these tracers are not linear : particle scavenging or advection of a water mass which is depleted (or enriched) in these tracers study of 230 Th / 231 Pa ratios (dissolved + particulate phases) « story » of the water masses + sinking particles (= flux studies) Chronometers of particle and water mass transport: Th and Pa isotopes

Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS Cosmogenics 3 He 238 U 234 Th 234 U 230 Th 226 Ra 232 Th 228 R a 228 T h 230 T h 234 U 238 U 234 Th 235 U 231 P a Litho. sources: Nd, lead isotopes, REE patterns, elemental abundances Water mass pathways: 228/226 Ra, Pa,Th, lead and Nd isotopes Biogenic flux: Ba, Si, POC Particle transport : Pa, Th, 228/226 Ra in barite, lead and Nd isotopes, 3 He 210 Pb 226 Ra Fe isotopes Simultaneous analysis of all these tracers on sediment samples, marine particles and seawater Information on sources and pathways of the analysed material Multi-tracers approach

Catherine Jeandel, Marseille 2004: Geochemistry in KEOPS M2 D6 D5 D4 D3 D2 D1 A5 A1 A11 B11 C11 C1 B1 C4 B4 - water samples : 24 x Niskin bottles - particles : 7 LVP (4 x 293mm ; 3 x 142 mm) Tom pump for surface samples (water ; particles) + sediment traps Ba, Sr …: 30 ml REE: 500 ml 234 Th: 5l Fe isotopes: 4 l Nd isotopes: 10 l Pa/Th: 20 l Ra isotopes: 50 l Cerege is missing! surface-bottom profiles at stations D6, D4 / C1, C4, C11 ; B4, B11 ; A5, A11 - track the water mass enriched in Fe (origin, transport …) - study of the downward particle flux (origin, sinking rate …)