This appendix reproduces recommendations made earlier, which are relevant to the global fiducial network. The recommendations made in the present report are essentially consistent with the results of these previous studies.
In 1988 the Task Group on Earth Sciences of the Space Science Board, National Research Council, produced a seminal report entitled Mission to Planet Earth. The primary research objectives of this mission are addressed in terms of four “Grand Themes,” which are:
To determine the composition, structure, and dynamics of the Earth 's interior and crust, and to understand the processes by which the Earth evolved to its present state.
To establish and understand the structure, dynamics, and chemistry of the oceans, atmosphere, and cryosphere and their interactions with the solid Earth, including the global hydrological cycle, weather, and climate.
To characterize the interactions of living organisms among themselves and with the physical environment, including their effects on the composition, dynamics, and evolution of the oceans, atmosphere, and crust.
To monitor and understand the interaction of human activities with the natural environment.