Out of one of mankind’s greatest scientific understandings, that matter and energy are fundamentally tied together, sprang the most terrifying weapon ever invented: the nuclear bomb. Yet from this horror has sprung what must be surely one of our most noble endeavors – the Comprehensive Test Ban Treaty (CTBT), which is a promise by nations to one another not to test and deploy such weapons against each other. It is a great credit to our world that since the moratorium in 1992 and inception of the treaty in 1996 only a handful of nuclear tests have been conducted and only by nations who had not then, or still have not signed the treaty. In the first thirteen years of the twenty first century, only three nuclear explosions, all conducted and claimed by the Democratic People’s Republic of North Korea, have disturbed the nuclear silence. The CTBT is a promise of peace that transcends short-sighted rivalries and disagreements between nations and ought to be lauded as one of the greatest achievements of diplomacy in the late twentieth century.



Enforcement of the treaty and international trust in it is also a marvel of technology. The International Monitoring System (IMS) is a worldwide network of seismometers, hydrophones, infrasound arrays and chemical and isotope detection units which listen, 24 hours a day, 365 days a year, to ensure that illicit nuclear activities will always be detected so that their perpetrators can be identified and brought to international justice. As a consequence, the ears of all nations are tuned to the earth and seas, and it is amazing what else, in the happy absence of nuclear explosions, they can hear.



It turns out that the hydro-acoustic part of the IMS, composed of 5 hydro-acoustic stations each made up of multiple triplets of hydrophones located around the world, has never been needed to detect an undersea explosion. But it does hear whales. The songs of whales travel thousands of miles through the oceans to arrive at IMS hydrophones. In one of the most beautiful technical circles ever closed, human beings learned to build bombs, promised each other never to use them, built a system to ensure that nobody could cheat, and, in doing so, are rewarded by a peek into an elegant and mysterious biological culture with which we might also, someday, live in peace.



As far as detecting bombs goes, whale songs are noise on the IMS network. They are often registered in exactly the frequency bands that the network is tuned to record, and they can interfere with the location of the hundreds of non-nuclear seismic events (earthquakes) which the network must catalogue each day lest a nuclear event be lost in the earth’s natural rumblings. This “noise,” however, contains a rich source of information for marine biologists. A data analysis system could be built (per this proposed study) which mirrors the International Data Centre data crunching machinery, but, instead of being focused on locating nuclear events and earthquakes, it could be tuned to understanding biological signals. The result would be a better understanding of whales, their communication, migration patterns and even, perhaps, the personal habits of individual cetaceans.



Science wouldn’t stop there, however, because the whale songs provide a predictable set of source signals which could be used to refine our understanding of the propagation of sounds in the oceans (which would feed back into nuclear-event resolution capacity). And finally, because the migratory patterns of whales are thought to remain constant over long periods, monitoring fluctuations in how the songs are received over decades could contribute to an understanding of how sound transmission in the oceans changes over time. Since transmission speeds and attenuation are thought to be largely a function of temperature, the long-term monitoring of songs could give us insight into how the oceans are changing in response to global warming. It is notable that an earlier attempt at doing just this, using man-made noise sources to monitor sound-propagation in the oceans to monitor temperature (the ATOC project), was thwarted to some extent by the activism of people concerned about the health effect of acoustic noise on whales. It is ironic, then, in a happily convergent way, that the whales themselves could provide the signals to study temperature, thus reconciling social differences, advancing science, and benefiting both climate scientists and animal enthusiasts with information about both subjects.



Using the IMS network to listen to whales is a rich project indeed, and especially fitting in what is hoped will become a world of peace and true nuclear silence.



Chatelet is partnering with Dr. Ronan LeBras, a seismologist and software engineer at the University of Vienna and the CTBTO, as well as the company Gydatos, on this project. (Go to the Gydatos website here.) The official title of the project proposal is Ocean Acoustics using Active Biological Sources recorded at IMS Hydrophones.

 

The Baleakanta Project has its own website at: www.baleakanta.org.​