Analysis of DPRK announced nuclear test and monsoon early warning among topics presented at AGU 2017

Ronan Le Bras, Software Engineer, CTBTO
Briefing on DPRK sixth announced nuclear test
Jolanta Kusmierczyk-Michulec, Atmospheric Sciences Officer, CTBTO
Lucrezia Terzi, SCK.CEN, and Simona Bordoni, Caltech

Several CTBTO scientists participated in the American Geophysical Union’s 2017 fall meeting (AGU 2017) which took place in New Orleans 11 – 15 December with the motto: “What will you discover?” The AGU fall meeting is the largest annual gathering of earth and space scientists and attracted around 24,000 participants. CTBTO scientists presented posters and participated in a number of activities and presentations.

A “Late Breaking” Session on the 3 September 2017 DPRK announced nuclear test attracted around 150 participants and offered an opportunity for CTBTO to present their latest findings on the subject. Numerous researchers from around the world presented their analysis on the event, as well as subsequent seismic events in the region. Analyses of the announced nuclear test were in agreement in terms of its magnitude, explosive characteristics and interferometry analyses which strongly indicated that the test was conducted at some depth below the peak of Mt Mantap located within the Punggye-ri Test Site. Further research in determining the emplacement conditions, seismic attenuation in the region and the depth at which the test was conducted (also using infrasound observations) as a means to better estimate the yield of the event, are ongoing. There was also consensus that the event occurring 8.5 minutes after the announced test was a collapse event while subsequent events in the area are tectonic in nature with the possibility that they may have been induced. CTBTO data was at the forefront in all waveform analyses undertaken, in particular from the seismic array KSRS located in South Korea and the seismic and infrasound arrays located at Ussuriysk, Russian Federation.

Ronan Le Bras, Software Engineer, CTBTO
AGU2017 fall meeting
Jolanta Kusmierczyk-Michulec, Atmospheric Sciences Officer, CTBTO

There was strong interest from both the research community and exhibitors in the International Monitoring System, in particular its build-up, current capability and future plans for its further establishment, especially in light of the importance of its data for analysing nuclear tests and its strong detection capability worldwide.

A second session included a presentation on radionuclide analysis and Atmospheric Transport Modelling (ATM), in particular to investigate the episodes of elevated levels of radioxenon. 

Other sessions that referenced CTBT data included an oral presentation about numerical calculation of two-dimensional hydroacoustic propagation on a sphere, a poster on whales using data recorded at HA04 (Crozet), and a poster on “Global atmospheric monitoring of noble gases: insight into processes from the Northern to the Southern Hemisphere” – a topic on which there is not yet much awareness and which generated interesting discussion.  The sessions also offered an opportunity to present the possibilities of accessing CTBT data to scientists, for instance through the virtual Data Exploitation Centre (vDEC).

David Jepsen, Coordinator, International Monitoring System Division, CTBTO

A study on “Atmospheric 7Be Concentration Changes as a Possible New Indicator for Early Warning on Indian Monsoon Onset” by Lucrezia Terzi of the Belgian Nuclear Research Centre (SCK.CEN) using CTBTO data, generated significant interest among scientists. Several monsoon experts described the work as “ground breaking”. The scientists found that by studying levels of the naturally occurring radioactive isotope Beryllium-7 (which poses no risk to human health or the environment), they are able to predict meteorological phenomena, such as the start of the monsoon season, with much greater accuracy and much earlier than is currently the case. Potential applications of this research include agricultural planning and forecasting (for planting season and harvesting), air quality and reservoir monitoring, as well as an improvement of public health and infrastructure management. A presentation of the findings is available here and a short news piece on the topic is available here.

Regular exchange by CTBTO with the wider scientific community ensures that the most up-to-date methods and applications are used in fulfilling the Organization’s mandate, as well as raising awareness of the wide range of applications of IMS data – from detecting nuclear tests to monitoring climate, tsunami early warning, volcano activity, and much more.