Feature Publication Archive
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Wilcock, W.S.D., R.P. Dziak, M. Tolstoy, W.W. Chadwick, Jr., S.L. Nooner, D.R. Bohnenstiehl, J. Caplan-Auerbach, F. Waldhauser, A.F. Arnulf, C. Baillard, T.-K. Lau, J.H. Haxel, Y.J. Tan, C. Garcia, S. Levy, and M.E. Mann (2018): The recent volcanic history of Axial Seamount: Geophysical insights into past eruption dynamics with an eye toward enhanced observations of future eruptions. Oceanography, 31 (1), 114–123, doi:10.5670/oceanog.2018.117.
Studies of underwater eruptions are essential to understand the processes that form oceanic crust, and the role submarine volcanoes have in exchanging heat and chemicals with the ocean and in supporting chemosynthetic biological communities. The Ocean Observatories Initiative (OOI) Cabled Array at Axial Seamount is the world’s most advanced underwater volcano observatory, building upon 30+ years of sustained geophysical monitoring at this site with autonomous and remote systems as part of PMEL’s New Millennium... more »
Weirathmueller, M.J., K.M. Stafford, W.S.D. Wilcock, R.P. Dziak, and A.M. Tréhu (2017): Spatial and temporal trends in fin whale vocalizations recorded in the NE Pacific Ocean between 2003-2013. PLoS ONE, 12 (10), e0186127, doi:10.1371/journal.pone.0186127.
Fin whales (Balaenoptera physalus) spend most of their lives ranging widely throughout ocean basins and thus can be extremely difficult to study. Nevertheless, understanding the fin whales’ population structure is of particular importance for management and recovery efforts due to their status as endangered under the U.S. Endangered Species Act.
Fin whales produce relatively simple, repeated signals that appear to have not changed significantly over time. The most commonly observed vocalization produced by fin whales—the “20 Hz pulse”—has been recorded throughout the world’... more »
Dziak, R.P., J.H. Haxel, H. Matsumoto, T.-K. Lau, S. Heimlich, S. Nieukirk, D.K. Mellinger, J. Osse, C. Meinig, N. Delich, and S. Stalin (2017): Ambient sound at Challenger Deep, Mariana Trench.Oceanography, 30 (2), doi:10.5670/oceanog.2017.240.
You might imagine the bottom of the ocean’s deepest point, seven miles down, to be a very quiet place. However, NOAA and partner scientists, making the first recordings from the Challenger Deep trough in the Mariana Trench in the Pacific Ocean, found something remarkably different: a wide variety of human-caused and natural sounds, including the hum of ship propellers, active sonar, earthquakes, baleen whales, and a category 4 typhoon passing near the sensor.
Human-generated noise has increased steadily over the past several decades. This project, which was funded by the NOAA Office... more »
Dziak, R.P., D.R. Bohnenstiehl, E.T. Baker, H. Matsumoto, J. Caplan-Auerbach, R.W. Embley, S.G. Merle, S.L. Walker, T.-K. Lau, and W.W. Chadwick, Jr. (2015): Long-term explosive degassing and debris flow activity at West Mata submarine volcano. Geophys. Res. Lett., 42(5), doi:10.1002/2014GL062603.
Even though ~75% of Earth's volcanic activity occurs below the sea surface, many questions remain on the longevity and acoustic characteristics of explosive seafloor eruptions. To date, only two active eruptions have ever been observed visually in the deep-ocean (>500 m) volcanoes, and then only over time periods of hours to days. The discovery of the actively erupting West Mata volcano in the NE Lau Basin near Samoa offered a rare opportunity to investigate a deep-ocean, explosive eruption. Video images of West Mata collected by remotely operated vehicle (ROV) provided unprecedented... more »
Matsumoto, H., D.R. Bohnenstiehl, J. Tournadre, R.P. Dziak, J.H. Haxel, T.-K.A. Lau, M. Fowler, and S.A. Salo (2014): Antarctic icebergs: A significant natural sound source in the Pacific Ocean. Geochem. Geophys. Geosyst., 15, doi: 10.1002/2014GC005454.
Previous research indicates that low-frequency ocean noise levels have risen 3 to 4 times since the early 1960s in some areas. This rise has been largely attributed to increased global ship traffic. The scientific community has become increasingly concerned about the adverse effects of anthropogenic (human-made) inputs to the marine ecosystem, and in particular to marine animals, which rely on sound to aid in migration, feeding, and breeding.