---

This topical volume focuses on the most recent advances that have been achieved in relevant fields of research of nuclear test ban monitoring, including seismology, infrasound- and hydro-acoustics, as well as nuclear physics and atmospheric backtracking. This research has been presented during the special sessions on "Research and Development in Nuclear Explosion Monitoring" convened during the 2007 and 2008 General Assemblies of the European Geosciences Union (EGU). The special sessions were introduced after the Preparatory Commission for the Comprehensive Nuclear Test-Ban Treaty Organization (CTBTO Prepcom) had convened a scientific symposium in 2006 on "CTBT: Synergies with Science 1996-2006 and beyond" marking the tenth anniversary of the United Nations General Assembly´s adoption of the CTBT Treaty. With regard to the seismo-acoustic fields several papers provide important updates on advances made in these fields since publication of ´Monitoring the Comprehensive Nuclear-Test-Ban Treaty´ (see PAGEOPH topical volumes 158-159, 2001-2002). Moreover, this topical volume expands on these publications by including radionuclide and noble gas monitoring, as well as atmospheric transport modeling. In these two areas, significant progress has been made in recent years. Two papers studying the 2006 North Korean nuclear test elucidate how progress made in the relevant fields has allowed for a good understanding on the characteristics of this underground nuclear test.

---

Introduction (A. Becker, B. Schurr, M. B. Kalinowski, K. Koch, D. Brown).- A. Seismo-acoustic Studies.- Considerations in phase estimation and event location using small-aperture regional seismic arrays (S. J. Gibbons, T. Kv‘rna, F. Ringdal).- Analysis of Signals from a unique ground-truth infrasound source observed at IMS Station IS26 in Southern Germany (K. Koch).- Detection and analysis of near-surface explosions on the Kola Peninsula (S. J. Gibbons, F. Ringdal).- The temporal morphology of infrasound propagation (D. P. Drob, M. Garcés, M. Hedlin, N. Brachet).- B. Radionuclide Monitoring Studies.- Underground nuclear explosions and release of radioactive noble gases (Y. Dubasov).- Genesis and equilibrium of natural lithospheric radioxenon and its influence on subsurface noble gas samples for CTBT on-site inspections (S. Hebel).- Ten years of development of equipment for measurement of atmospheric radioactive xenon for the verification of the CTBT (M. Auer, T. Kumberg, H. Sartorius, B. Wernsperger, C.Schlosser).- Krypton and xenon radionuclides monitoring in the North-West region of Russia (Y. Dubasov).- Environmental radioxenon levels in Europe - a comprehensive overview (P. R.J. Saey, C. Schlosser, P. Achim, M. Auer, A. Axelsson, A. Becker, X. Blanchard, G. Brachet, L. Cella, L.-E. De Geer, M. B. Kalinowski, G. Le Petit, J. Peterson, V. Popov, Y. Popov, A. Ringbom, H. Sartorius, T. Taffary, M. Zähringer).- Discrimination of nuclear explosions against civilian sources based on atmospheric xenon isotopic activity ratios (M. Kalinowski, A. Axelsson, M. Bean, X. Blanchard, T. W. Bowyer, G. Brachet, S. Hebel, J. I. McIntyre, J. Peters, C. Pistner, M. Raith, A. Ringbom, P. R.J. Saey, C. Schlosser, T. J. Stocki, T. Taffary, K. Ungar).- Computation and analysis of the global distribution of the radioxenon isotope 133-xenon based on an emissions from nuclear power plants and isotope production facilities and its relevance for the verification of the nuclear test ban treaty (G. Wotawa, A. Becker, M. B. Kalinowski, P. R.J. Saey, M. Tuma, M. Zähringer).- Radioxenon time series and meteorological pattern analysis for CTBT event categorisation (W. Plastino, R. Plenteda, G. Azzari, A. Becker, P. R. J. Saey).- C. Case Studies.- Estimation of explosion energy yield at Chernobyl Nuclear Power Plant accident (S. A. Pakhomov, Y. V. Dubasov).- Backtracking of noble gas measurements taken in the aftermath of the announced October 2006 event in North Korea by means of PTS methods in nuclear source estimation and reconstruction (A. Becker, G. Wotawa, A. Ringbom, P. R.J. Saey).- Satellite Earth observations support CTBT monitoring: a case study of the nuclear test in North Korea of Oct. 9, 2006 and comparison with seismic results (J. Schlittenhardt, M. Canty, I. Grünberg).

---