Theme 1: The Earth as a complex system

Theme 1: The Earth as a complex system

Scientific and technical advances in monitoring the globe for nuclear explosions require a deep understanding of the way in which features of the Earth influence the relevant signals as they travel from their point of origin to where they are observed. The signals from monitoring networks, as well as noise, constitute a huge database and support advances in the Earth Sciences on global, regional and local scales.

Seismic and acoustic signals propagate through the Earth, its atmosphere and its oceans. The Earth’s atmosphere also transports radioactive materials around the globe in minute concentrations, and its properties are relevant for different kinds of satellite observations.

This Theme focuses on any dynamic or static properties of the Earth that can be observed with seismic, hydroacoustic and infrasound data, with radionuclide tracer observations, with on-site geophysical measurements or with other monitoring data. Studying these Earth properties in turn helps to improve the processing or interpretation of monitoring data.

Many elements of the current monitoring effort are also used in other contexts, for example in the characterization of earthquakes, in the study of climate change, in the measurement of atmospheric transport, and in the monitoring of releases from nuclear facilities. Such civil and scientific uses of IMS data and IDC products are also brought together under this Theme.


  • T1.1 Infrasound and Atmospheric Dynamics
    Infrasound propagation; corresponding atmospheric models

  • T1.2 Solid Earth Structure
    Velocity models and their development; waveform travel-time, azimuth and slowness corrections; the use of ground-truth events; regional structure; attenuation of seismic signals; acoustic properties of the oceans 

  • T1.3 Atmospheric and Subsurface Radionuclide Dispersion and Depletion
    Atmospheric Transport Modelling (ATM); radionuclide deposition; subsurface radionuclide transport; other aspects of radionuclide dispersion

  • T1.4 Exploratory Drilling Techniques for On-Site Inspection
    Drilling technologies for investigating petrophysical and other rock properties; lessons from the extractive industries; sample extraction and handling

  • T1.5 Civil and Scientific Applications of IMS data and IDC Products
    IMS data and IDC products used for non-verification-related applications such as tsunami warning, volcanic ash detection and warning, radiological emergencies and response, climate research. seismic hazard assessment, bolides, marine mammal migration