Geotraces

The concept of cycle describes the pathway by which a chemical element moves through the three major compartments of Earth (such as continents, atmosphere, and ocean).

Because these cycles are directly related to climate dynamics and are heavily impacted by global change, it is essential to quantify them.

Some of these trace elements are directly linked to climate via, for example, their role as essential nutrients for life; others allow quantification of ocean processes (origin and dynamics of matter, age of water masses, etc.

Trace elements serve as regulators of biological processes in the ocean, influencing marine ecosystem dynamics and the carbon cycle.

GEOTRACES is quantifying the supply, removal, internal cycling, chemical form and distribution of essential micronutrients and other trace elements.

Benefits will be realised by pursuing two overarching goals: The central component of GEOTRACES is a series of cruises spanning the global ocean and sampling the full water column.

These dedicated GEOTRACES cruises collect seawater for analysis of a wide range of trace element and isotopes.

The main motivation for distributing the product at this time is to strengthen and intensify collaboration with the broader ocean research community.

The eGEOTRACES Electronic Atlas (available at www.egeotraces.org) is based on the digital data package and provides 2D and 3D images of the ocean distribution of many of the parameters.

In addition, eGEOTRACES can help in teaching and outreach activities and can also facilitate conveying societally relevant scientific results to interested laymen or decision makers.

This 3D scene shows the distribution of dissolved lead (Pb) in the Atlantic. At a depth of about 500 to 2,000 metres a red band runs across the Atlantic Ocean. It indicates relatively high lead concentrations. The increased concentrations are due to emissions of car exhaust gases in Europe and North America that found their way into the environment prior to the introduction of unleaded petrol. In the image South America is on the left while Africa is on the right.