- © 2013 by the Seismological Society of America
Peter Marshall, extraordinary seismologist, scientific leader, mentor, colleague, and friend, died on 5 October 2012 in Basingstoke, England. Peter spent his entire scientific career working on scientific issues related to the detection, identification, and yield estimation of underground nuclear explosions.
Peter’s greatest strength was in the careful study and interpretation of seismic data and waveforms. Once he trusted a body of data, he would apply his intellect and experience to gleaning the new insights and understandings hidden therein. Often he would bring separate, independent sets of data to a problem to reinforce or modify his original interpretation. Peter possessed an unsurpassed ability to explain his studies and their significance to his seismological colleagues and to government officials. Peter was a sustained contributor to the literature of seismic source identification and explosion yield estimation. His last contribution was published in the Bulletin of the Seismological Society of America in 2012.
Peter spent most of his professional career with the Atomic Weapons Establishment (AWE) of the Ministry of Defence of the United Kingdom (UK). Early in his career he worked on high‐explosive experiments designed to test the cavity decoupling concept developed in theoretical terms by scientists in the United States (US). This concept, and other perceived difficulties with seismic monitoring of nuclear tests, contributed to the underground environment being excluded from the Limited Test Ban Treaty (LTBT) of 1963. Peter continued to work on the seismological problems of test detection and identification and in 1972 was a coauthor on an early paper proposing and applying the MS:mb criterion for discrimination of underground tests from shallow earthquakes.
I first met Peter in the early 1970s during a time when the use of seismic arrays in test detection and identification was being developed. Peter was involved in the analysis of data from UK‐designed arrays in Canada, Scotland, Australia, and India, and he worked extensively with colleagues in the US, at Lincoln Laboratory and elsewhere, on the sharing of data and results from array studies.
In 1974, the Threshold Test Ban Treaty (TTBT), limiting tests to 150 kilotons, was signed between the US and the Union of Soviet Socialist Republics (USSR). This agreement was followed in the late 1970s by trilateral talks between the US, UK, and USSR on a more comprehensive accord. Peter served as a member of the UK delegation during the trilateral talks, and his knowledge and engaging manner did much to establish trust and open communication between the technical members of the delegations. At one otherwise stilted reception for the delegations, Peter provided the entertainment by drinking a scotch and water while upside down doing a handstand with his feet against a wall. Peter’s feat helped warm the atmosphere of the room and stimulate dialogue between the delegates.
Peter contributed to resolving a controversy that developed in the 1980s regarding adherence to the TTBT. There was concern in the US that the Soviets were testing above the 150‐kiloton limit. Peter’s hypothesis was that geologic conditions at the various test sites could influence seismic‐yield estimations. He worked with colleagues in the US, particularly at Lawrence Livermore Laboratories, to develop and publish his arguments. The Joint Verification Experiment (JVE) of 1988 confirmed his hypothesis. During the debate of this issue, I asked Peter what he honestly thought about compliance with the treaty. He replied, “Well, John, I’ll tell you what I told our Ministry of Defence—if anybody’s cheating, you couldn’t prove it in court.” In 1990, his government recognized his scientific contributions to this debate by awarding him membership in the Order of the British Empire (OBE).
The pinnacle of Peter’s career was reached with his leadership during the Comprehensive Nuclear‐Test‐Ban Treaty (CTBT) negotiations within the Conference of Disarmament (CD) in Geneva during 1994–1996. The conference consisted of 38 member states, each with its own national interests and its understanding of the technical issues involved in nuclear test monitoring. The work of the negotiations was carried out through a consensus building process in various working groups, each with a chairperson and a “Friend of the Chair” (FOC). Peter served as FOC for the verification working group and Chairman of the International Monitoring System (IMS) Expert Group. Peter’s experience in and understanding of the scientific and technical questions, his engaging and honest manner, and his infinite patience with delegates made him a central figure in the negotiations. He could not dictate the resolution of any contentious issue, but his suggestions and reasoned explanations of options in many cases led to acceptable solutions. At one stage, when the delegations seemed to be “at sixes and sevens” over the structure of the IMS, Peter was asked to address a plenary session with his vision of an effective and realizable verification system. His lucid and rational presentation received an unprecedented ovation from the delegations, and progress toward agreement on an IMS resumed. Near the end of the negotiations in 1996, when United Nations officials held a press conference on the status of the CTBT, Peter Marshall was the only scientist with them at the briefing table. For his work on the treaty, Peter was honored by being appointed a Companion in the Order of St. Michael and St. George (CMG).
Peter Marshall was a devoted husband and father, providing loving support and care to his wife Pam through her many years of serious medical challenges. Peter helped others facing similar challenges by serving in recent years as Chairman of the Oxford (England) Transplant Foundation. His daughter, two grandchildren, and a great grandchild survive him.
Peter Marshall was a warm and engaging person. He loved to tell anecdotes of his experiences and provide impersonations of notable persons. One always felt better after meeting with Peter and looked forward to the next opportunity to be in his company. Peter brought credit to the science of seismology through the application of its data and discoveries to help ensure a better world for posterity. It is hard to imagine that world today without Peter Marshall in it, but it is great comfort to hold and cherish the memory of knowing and working with this great man.