eGEOTRACES

Factsheet #11: Protactinium

Find below a summary of main GEOTRACES findings and products on protactinium research:

Atlas

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3D scenes showing the distribution of dissolved iron in the Atlantic and the Pacific, the Arctic Oceans. In warm colours (red, orange, etc.) you can view high concentrations of dissolved protactinium-231.

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on protactinium research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on protactinium-231:

Factsheet #10: Thorium

In the marine environment, the different elements of the natural radioactive families of uranium (U)and thorium (Th) can be classified into two groups: those that are soluble in seawater and those that are particle-reactive, extracted from the water column by chemical and biological processes (adsorption, aggregation, precipitation).

Thorium isotopes are very reactive toward particles in the marine environment. In seawater, thorium is present as Th(OH)4 oxide and adsorbs on all solid surfaces.

Thorium isotopes have different half-lives:
234Th: T1/2 = 24.1 days
232Th: T1/2 = 1.4 1010 years
230Th: T1/2 = 7.5 104 years

Thorium-232 (232Th) is the most abundant and is brought to the ocean in detrital form by rivers and the atmosphere. 232Th, coming from terrigenous dust, is directly associated with particles in the ocean. It is mostly transported by detrital matter. In the earth’s crust its concentration is of the order of 10.7 ppm but in sea water it is less than 0.7 ppt Thus, this isotope is used in marine geochemistry to quantify the so-called lithogenic contributions (from the erosion of rocks).

Thorium-234 (234Th) and Thorium-230 (230Th) are produced in situ (in dissolved form) by radioactive decay of Uranium-238 (238U) and Uranium-234(234U) by alpha emission. The concentrations of 238U and 234U are constant in the ocean, these nuclides represent homogeneous sources of 234Th and 230Th in the water column. These thorium isotopes, produced in situ, rapidly leave the seawater by attaching to marine particles. In this form, they become tracers of particulate matter. Therefore, the use of U/Th imbalances allows the study of:

  • Particle fall rate and calibration of particle traps
  • Estimation of exported production
  • Interaction processes between solution and marine particles
  • Ventilation of intermediate and deep waters

Find below a summary of main GEOTRACES findings and products on thorium research:

Atlas

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Thorium-230

Thorium-232

Thorium-234

3D scenes showing the distribution of 230Th, 232Th and 234th in the Atlantic, the Pacific and the Arctic Oceans. In warm colours (red, orange, etc.) you can view high concentrations of dissolved thorium.

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on thorium research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on dissolved thorium:

Factsheet #9: Neodymium

Find below a summary of main GEOTRACES findings and products on neodymium research:

Atlas

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3D scenes showing the distribution of dissolved iron in the Atlantic and the Pacific. In warm colours (red, orange, etc.) you can view high concentrations of dissolved neodymium.

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on neodymium research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on dissolved neodymium:

Factsheet #8: Dissolved Nickel

Find below a summary of main GEOTRACES findings and products on nickel research:

Atlas

(The images below may not show if you are using Safari. Please change your browser if necessary).

3D scenes showing the distribution of dissolved iron in the Atlantic and the Pacific. In warm colours (red, orange, etc.) you can view high concentrations of dissolved nickel.

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on nickel research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on dissolved nickel:

Factsheet #7: Dissolved Manganese

Find below a summary of main GEOTRACES findings and products on manganese research:

Atlas

(The images below may not show if you are using Safari. Please change your browser if necessary).

3D scenes showing the distribution of dissolved iron in the Atlantic and the Pacific. In warm colours (red, orange, etc.) you can view high concentrations of dissolved manganese.

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on manganese research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on dissolved manganese:

Factsheet #6: Dissolved Cobalt

Find below a summary of main GEOTRACES findings and products on cobalt research:

Atlas

(The images below may not show if you are using Safari. Please change your browser if necessary).

3D scenes showing the distribution of dissolved iron in the Atlantic and the Pacific. In warm colours (red, orange, etc.) you can view high concentrations of dissolved cobalt.

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on cobalt research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on dissolved cobalt:

Factsheet #5: Dissolved Zinc

Find below a summary of main GEOTRACES findings and products on zinc research:

Atlas

(The images below may not show if you are using Safari. Please change your browser if necessary).

3D scenes showing the distribution of dissolved zinc in the Atlantic and the Pacific. In warm colours (red, orange, etc.) you can view high concentrations of dissolved zinc.

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on zinc research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on dissolved iron:

Factsheet #4: Dissolved Cadmium

Atlas

(The images below may not show if you are using Safari. Please change your browser if necessary).

3D scenes showing the distribution of dissolved cadmium in the Atlantic, Pacific Indian and Arctic Oceans. In warm colours (red, orange, etc.) you can view high concentrations of dissolved Cadium.

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on cadmium research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on dissolved cadmium:

Factsheet #12: Radium isotopes

Naturally occurring radium isotopes allow the study of short and long term processes in the ocean. Radium is produced by the decay of thorium mainly in the sediments but also in the water column. In the ocean, thorium is produced by the decay of uranium directly present in the water column. Thorium have a strong affinity for particles and is adsorbed on the particles. Then thorium is transported to the bottom and slowly accumulates in the sediments. Having an affinity for the dissolved phase, radium, produced in the sediments, diffuses to the water column at the margins and into the deep ocean. Therefore, radium concentrations are generally high near the sediments, in freshwater discharges to the ocean and in circulating waters through the sediments, and are low in the open ocean. Water masses in contact with sediments become enriched in radium. Radium isotopes can be used to trade different processes.

The isotopes radium-224 (224Ra) and radium-223 (223Ra), because of their short half-lives, remain in the ocean about 2 or 3 weeks and 2 months, respectively. They are detected mainly at the interfaces (sediment, surface, margins. . .) and in the first 100 km offshore in the mixed layer. These two isotopes can be used to quantify freshwater discharge fluxes at sea and circulation waters through sediments, to estimate the residence time in the coastal zone, horizontal transports from the coast to the open sea gradient.

Radium-228 (228Ra) has a longer half-life which allows it to reach the open ocean. 228Ra can be measured up to about 30 years after its release from the sediments. The highest activities of 228Ra are observed at the surface due to surface transport from continental margins, rivers, freshwater discharges, and recirculating water in the sediments. Fluxes of 228Ra from springs and, more generally, from continental margins to the open ocean can be converted to fluxes of trace elements such as iron.

Radium-226 (226Ra) has the longest half-life. 226Ra activities increase with depth, which is mainly explained by diffusion from deep sediments. 226Ra activities vary from one basin to another depending on the water masses and their origins. Bottom waters get enriched with 226Ra along the path of the thermohaline circulation between the North Atlantic and the North Pacific. The transit time of water from the North Atlantic to the North Pacific is about 1000 years. This transit time is similar to the half-life of 226Ra and makes it a potential tracer of this global circulation and water masses.

Find below a summary of main GEOTRACES findings and products on radium research:

Atlas

North Atlantic Ocean:

Pacific Ocean:

3D scenes showing the distribution of dissolved radium-226 and radium-228 in the North Atlantic and the Pacific. In warm colours (red, orange, etc.) you can view high activities of dissolved radium.

(The images below may not show if you are using Safari. Please change your browser if necessary).

Data

Data is available to download after registration here: https://geotraces.webodv.awi.de/login

Discoveries include:

Below you can find a list of science highlights of main GEOTRACES discoveries on radium research:

Intense benthic nepheloid layers in the Northwest Atlantic Ocean lead to unexpected distributions of dissolved and particulate thorium-230 and protactinium-231

Chen and colleagues explore the behaviour of thorium-230 and protactinium-231 in the benthic nepheloid layers…

Measuring actinium-227 by mass spectrometry is feasible, sensitive and reliable!

Levier and co-authors have developed a new protocol measurement of the dissolved actinium in seawater.

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

Isopycnal mixing controls protactinium and thorium distributions in the Pacific Southern Ocean

Pavia and co-workers determined the physical and chemical speciation as well as the vertical distribution of Protactinium-231 and Thorium-230 at 12 stations across the Southern Pacific Antarctic Circumpolar Current…

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

List of publications

Scroll down to view the list of GEOTRACES publications on radium isotopes:

Rechercher