Geoscience Reference
In-Depth Information
the interdisciplinary approaches is likely to accelerate progress, much as has been the
case for studies of the present-day deep Earth system. The complexity and energetics
of the early Earth are distinct from today, and disciplinary approaches need to be
informed by the geosystems perspective that an interdisciplinary context can provide.
An Early Earth initiative could build on existing community organizations and
funding programs, but distinct focus is required to catalyze coordinated momentum in
this arena.
THERMO-CHEMICAL INTERNAL DYNAMICS
AND VOLATILE DISTRIBUTION
The elucidation of plate tectonics over the past 50 years has provided a
general framework for understanding shallow Earth structures, kinematics, and
processes and for relating observations of the present Earth to those preserved in the
geological record. The quests to fully quantify three-dimensional plate dynamics and
to determine how distribution of materials at Earth's surface evolves with the internal
dynamic system remain primary goals of the Earth sciences. The dynamic
configuration, thermal and chemical fluxes, and driving forces within Earth's interior
are all of central importance to understanding our planet's evolution, but these must
be deduced from observations made at the surface. An improved understanding of
thermo-chemical internal dynamics and volatile distribution within Earth also has
important societal implications for the mitigation of volcanic and earthquake hazards
and for the discovery and development of mineral and geothermal resources.
Making progress has required parallel maturation of a suite of disciplines that
bring key information to light: seismology to image elastic and anelastic properties
and material heterogeneity throughout the interior, mineral physics to characterize
thermo-elastic properties, phase equilibria, electronic transitions, and transport
properties of Earth materials over the full pressure-temperature range of the interior,
geodynamics to quantify dynamic behavior of deep thermo-chemical systems and
their surface manifestations, geomagnetism to probe the flow field of the outer core
material and to constrain temporal evolution of the geodynamo, geochemistry to
define internal chemical variability and timing of fractionation events, and geology to
decipher the history of crustal formation and plate tectonics recorded by surface
rocks. As observational, laboratory, and modeling capabilities of these disciplines
have expanded, the prospects for major advances in our understanding of Earth's
internal dynamics have increased, and a concerted interdisciplinary effort over the
next decade holds the promise of significant impact on fundamental questions such
as:
How long has plate tectonics been in operation, as we see it today?
What is the style of mantle convection and material flux between the upper
and lower mantles?
How is chemical heterogeneity distributed in the mantle, how and when was it
created, and what is its role in the dynamic circulation?
What is the volatile budget of the deep Earth?
Search WWH ::




Custom Search