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August 24, 2021

The left panel shows the model of maximum tsunami inundation depth at South Beach for the 1700 CE event and on the right a zoomed-in view of the tsunami inundation depth at Mike Miller State Park. Gray dotted circles show location of trees used in this study on the north side of the stand. Colors on the map show inundation depth from the model, implying 0–10 m of inundation depth at the Mike Miller Park Douglas-fir stand. Green areas are high ground locations that show no inundation. Dziak et al. 2021

 A stand of old growth Douglas-firs near a pond in Mike Miller Park in South Beach, Oregon

August 24, 2021

Core samples taken from a stand of old growth Douglas-fir trees in the South Beach area just south of Newport showed reduced growth following the 9.0 earthquake and subsequent tsunami that struck the Pacific Northwest in 1700.

The physical evidence from the Douglas-fir tree rings confirms modeling that depicts the reach of the January 1700 quake, which was the last major earthquake to hit the Cascadia Subduction Zone, said Robert Dziak, NOAA PMEL Acoustic Program lead. 

“The tsunami appears to be the event that most affected the trees’ growth that year,” said Dziak, whose work includes ocean acoustic studies, signal analysis and tsunami modeling. He also holds a courtesy appointment in Oregon State University’s College of Earth, Ocean, and Atmospheric Sciences. “Getting these little bits of the picture helps us understand what we might expect when the next ‘big one’ hits.”

The findings were published recently in the journal Natural Hazards and Earth System Sciences.

The idea for the study dates back more than a decade; Dziak was aware of past research that had shown evidence of the 1700 quake in trees in Washington, and thought it might be worth seeing if similar evidence existed in Oregon.

The first challenge was finding a stand of old growth Douglas-firs in the tsunami inundation zone. The researchers looked at a few places before locating the stand in Mike Miller Park in South Beach, about two kilometers south of Yaquina Bay and 1.2 kilometers east of the present-day ocean shoreline.

“We’re not sure why this tree stand wasn’t logged over the years, but we’re very fortunate to have a site so close to the coastline that has survived,” said coauthor Bryan Black of the Laboratory of Tree-Ring Research at the University of Arizona, Tucson.  

A new and updated tsunami model run by the researchers as part of the study shows that the area could have been inundated by up to 10 meters of water in the 1700 tsunami event, said Dziak.

Once the old growth stand was identified, the researchers collected core samples from about 38 trees using a process that allows them to analyze the tree rings without damaging the overall health of the trees. The majority of the trees dated to around 1670, with one dating to 1650, Dziak said.

They analyzed the growth rates in the rings and compared the growth rates to those of other old-growth Douglas-firs at sites not in the tsunami inundation zone. They found that in 1700 the trees in the tsunami inundation zone showed a significantly reduced growth rate.

Researchers are still working to figure out why the tsunami might have affected the trees’ growth since the trees are relatively far from the shoreline. They suspect it may be a combination of the ground shaking from the earthquake and the inundation of seawater.

“The salty seawater from a tsunami typically drains pretty quickly, but there is a pond area in Mike Miller Park where the seawater likely settled and remained for a longer period of time,” Dziak said.

Black added that the researchers’ next step is to conduct an isotopic analysis on the wood from 1700.

“We will look for signatures consistent with those found in trees that were inundated by the 2011 Tohoku tsunami in Japan,” he said. “If successful, we could develop a powerful new technique to map prehistoric tsunami run-up along the Pacific Northwest coast.”

Yong Wei of the University of Washington Cooperative Institute for Climate, Ocean and Ecosystem Studies and Susan Merle of the Cooperative Institute for Marine Resource Studies at Oregon State University’s Hatfield Marine Science Center are co-authors. 

Originally posted on OSU News on August 24, 2021

June 24, 2020
CLOSP lander on the deck of the DSSV Pressure Drop that houses scientific sensors. It is approximately 1 by 1.5 by 1.8 meters in size

The full-ocean depth hydrophone (top left) attached to the CLOSP lander along with a conductivity, temperature and depth sensor (CTD). The lander also stores geological and biological samples collected by the submersible. Photo Credit: Kathy Sullivan/Caladan Oceanic

July 08, 2020

PMEL Acoustics Program and Engineering Development Division participated as part of a memorandum of understanding between NOAA and Caladan providing subject matter expertise on pressure sensors and acoustics during the June mission in the Mariana Trench to map the Challenger Deep with pressure sensors and collect oceanographic data. A full-ocean depth hydrophone was deployed during the Ring of Fire Expedition at Challenger Deep.  The hydrophone was deployed on a lander with several deep-ocean pressure sensors over two  cruises in the Challenger Deep basin.  In addition, water samples for environmental DNA analysis have also been collected.

The first dive was completed on June 8 by Kathy Sullivan and Victor Vescovo aboard the Limiting Factor, a two-person submersible built by Triton Submarines and Caladan Oceanic. The recordings from the hydrophone are also part of acoustics research conducted by Woods Hole Oceanographic Institution to determine how sound waves propagate in the deepest parts of the ocean.  

PMEL successfully first deployed the hydrophone in 2015 to establish a baseline for noise in the ocean’s deepest location.  The recordings captured a baleen whale’s call, a magnitude 5.0 earthquake, an overhead typhoon and ship traffic noise.

PMEL Project: 

May 21, 2020
A master's student sitting in front of a computer looking at sound spectrogram on a computer from

Zoe Rand, currently a master’s student at St. Andrews University, analyzing acoustic data last summer. Zoe was working with Samara Haver and the PMEL Acoustics Program in Newport to analyze whale vocalizations in Cordell Bank National Marine Sanctuary. Photo Credit: Samara Haver (OSU/NOAA PMEL).

May 21, 2020

The coronavirus pandemic response has reduced pollution from a large number of sources across many geographic regions. NOAA has launched a wide-ranging research effort to investigate the impact of reduced vehicle traffic, air travel, shipping, manufacturing, and other activities on Earth's atmosphere and oceans. Researchers are using the most advanced atmosphere-ocean models to look for changes in atmospheric composition, weather, climate, and precipitation over weeks to months. In the oceans, NOAA scientists will be assessing impacts of reduced underwater noise levels on marine life.

PMEL along with NOAA Fisheries Office of Science and Technology, NOAA Sanctuaries and Department of Interior’s National Park Service are collaborating to analyze data from hydrophones deployed around the United States coastal waters to measure changes and assess any impacts on fisheries and marine mammal activity due to reduced maritime transportation and other maritime activities. 

Read the full story from NOAA Research.

PMEL Project: 

February 14, 2020
Ocean Sciences Meeting Banner with Wave Background
February 14, 2020

41 scientists from PMEL, including scientists from NOAA's cooperative institutes at the University of Washington's Joint Institute for the Study of the Ocean and Atmosphere (JISAO) and Oregon State University's Cooperative Institute for Marine Resources Studies (CIMRS), the National Research Council, graduate and undergraduate students are heading to the Ocean Sciences Meeting in San Diego to share their current research. Talks and posters cover a range of topics include saildrone research, ocean observing systems, marine heatwaves, Arctic, acoustics, Deep Argo, genetics and genomics, El Nino, hydrothermal vents, methane, nutrients, technologies, ocean carbon and data management.

The 2020 Oceans Science Meeting is the flagship conference for the ocean sciences and the larger ocean-connected community.  As we approach the UN Decade of Ocean Science for Sustainable Development, beginning in 2021, it is increasingly important to gather as a scientific community to raise awareness of the truly global dimension of the ocean, address environmental challenges, and set forth on a path towards a resilient planet. The meeting is co-sponsored by the American Geophysical Union (AGU), the Association for the Sciences of Limnology and Oceanography (ASLO), and The Oceanography Society (TOS).

PMEL research groups that will be present at the conference are: AcousticsArctic including Innovative Technology for Arctic ExplorationClimate-Weather InterfaceEarth-Ocean InteractionsEcoFOCIEngineering, Genetics and GenomicsGlobal Tropical Moored Buoy Array, , Large Scale Ocean PhysicsOcean CarbonOcean Climate StationsPacific Western Boundary Currents, and Science Data Integration Group.

November 20, 2019
Picture of a Teledyne Webb Research Slocum glider equipped with a hydrophone to record ocean sound.

Ocean gliders are a quiet and efficient mobile autonomous platform for passive acoustic monitoring and oceanographic measurements in remote marine environments. Researchers equipped a Teledyne Webb Research Slocum glider with a hydrophone to record sound along the US Pacific Northwest coast. 

November 20, 2019

NOAA and Oregon State University researchers have developed an effective method to use an underwater robotic glider to measure sound levels over broad areas of the ocean, published today in the journal PLOS ONE.

“Healthy marine ecosystems need to have noise levels within particular ranges,” said Joe Haxel, lead author of the paper and assistant professor/senior research at Oregon State University and part of NOAA’s Pacific Marine Environmental Lab Acoustics Program. “As an analogy for humans it’s the difference between living in the country or living in the city or somewhere really loud.”

Ocean sound was recently listed as an essential ocean variable by the Global Ocean Observing System, a UNESCO program, due to its importance for marine life and seagoing humans and because it is used to monitor and locate everything from earthquakes to tsunamis to nuclear explosions.

Traditionally, scientists have measured ocean sound by attaching hydrophones, essentially an underwater microphone, to a fixed mooring in the water. The problem with that is scientists only get data from that single location. Ocean sound can also be measured from a research ship, but they are expensive to operate. They also create a lot of noise themselves, which disturbs marine animals and fish that are sensitive to sound.

Attaching a hydrophone to a glider solves those problems because gliders operate autonomously, relatively quietly and can cover hundreds of miles over several weeks.

Gliders equipped with hydrophones can conduct repeated surveys of a region of concern for acoustic habitat degradation and provide real-time measurements of changing noise levels. Gliders have also successfully been used by scientists to measure noise from an underwater volcano and to predict surface wind speeds. An additional benefit of gliders is that they are outfitted with other sensors and instruments that provide important measurements, such as temperature, salinity and depth.

In the research described in the PLOS ONE paper, the research team attached the hydrophone to the glider, which is about 5 feet long and weighs about 120 pounds. The glider traveled for 18 days between Grey’s Harbor, Washington and Brookings, Oregon, a distance of about 285 miles. The glider operated along the North American continental shelf break, which on average is about 30 miles off the coast where the ocean depth begins to drop more steeply. The shelf break is a key migratory path for marine animals.

Once the scientists retrieved the hydrophone data, their main challenge was fine-tuning their algorithms to filter out the noise the glider creates when operating. After that filtering occurred, the researchers were able to cross-reference the data collected during the 18-day glider trip with historical data from hydrophones attached to moorings along that route.

Haxel said it was pretty shocking how closely the data sets aligned. That led the team to conclude that the gliders are an effective and valuable asset for measuring underwater ocean sound.       

Read the paper here:

The story was originally published by Oregon State University on November 20, 2019. 

PMEL Project: 

September 17, 2019
An underwater hydrophone prior to deployment in Glacier Bay National Park and Preserve.

Staging an autonomous underwater hydrophone for deployment in Glacier Bay National Park and Preserve. 

September 17, 2019

Storms, boat traffic, animal noises and more contribute to the underwater sound environment in the ocean, even in areas considered protected, a new study from Oregon State University, Cornelle University, National Park Service, and NOAA PMEL and NOAA Fisheries scientists shows.

Using underwater acoustic monitors, researchers listened in on Stellwagen Bank National Marine Sanctuary off the coast of Boston; Glacier Bay National Park and Preserve in Alaska; National Park of American Samoa; and Buck Island Reef National Monument in the Virgin Islands. They found that the ambient sounds varied widely across the sites and were driven by differences in animal vocalization rates, human activity and weather.

The findings demonstrate that sound monitoring is an effective tool for assessing conditions and monitoring changes, said Samara Haver, a doctoral candidate in the College of Agricultural Sciences at OSU and the study’s lead author. “This is a relatively economical way for us to get a ton of information about the environment,” said Haver, who studies marine acoustics and works out of the Cooperative Institute for Marine Resources Studies, a partnership between OSU and the National Oceanic and Atmospheric Administration at the Hatfield Marine Science Center in Newport. “Documenting current and potentially changing conditions in the ocean soundscape can provide important information for managing the ocean environment.”

Passive acoustic monitoring is seen as a cost-effective and low-impact method for monitoring the marine environment. The researchers’ goal was to test how effective acoustic monitoring would be for long-term assessment of underwater conditions.

“Ocean noise levels have been identified as a potential measure for effectiveness of conservation efforts, but until now comparing sound across different locations has been challenging,” Haver said. “Using equipment that was calibrated across all of the sites, we were able to compare the sound environments of these diverse areas in the ocean.”

The researchers collected low frequency, passive acoustic recordings from each of the locations between 2014 and 2018. They compared ambient sounds as well as sounds of humpback whales, a species commonly found in all four locations. The inclusion of the humpback whale sounds – mostly songs associated with mating in the southern waters, and feeding or social calls in the northern waters – gives researchers a way to compare the sounds of biological resources across all the soundscapes, Haver said. 

The researchers found that ambient sound levels varied across all four study sites and sound levels were driven by differences in animal vocalization rates, human activity and weather. The highest sound levels were found in Stellwagen Bank during the winter/spring, driven by higher animal sound rates, vessel activity and high wind speeds. The lowest sound levels were found in Glacier Bay in the summer.

“Generally, the Atlantic areas were louder, especially around Stellwagen, than the Pacific sites,” Haver said. “That makes sense, as there is generally more man-made sound activity in the Atlantic. There also was a lot of vessel noise in the Caribbean.”

The researchers also were able to hear how sound in the ocean changes before, during and after hurricanes and other severe storms; the monitoring equipment captured Hurricanes Maria and Irma in the Virgin Islands and Tropical Cyclone Winston in American Samoa. Ultimately, the study provides a baseline for these four regions and can be used for comparison over time. Documenting current and potentially changing conditions in the ocean soundscape can provide important information for managing the ocean environment, particularly in and around areas that have been designated as protected, Haver said.

This story was originally posted by Oregon State University: 

Learn more about PMEL's work with NOAA and National Park Service's Noise Reference Station here:

PMEL Project: 

July 11, 2019

Some of PMEL's summer undergraduates. Top Row: Ellen Lee, Harrison Knapp and Isabelle Chan. Bottom Row: Madeline Talebi and Sam Mogen. 

July 11, 2019

PMEL is excited to host seven undergraduates this summer from across the United States! They are working across various research groups studying ocean carbon, Madden-Julian oscillation impacts, meteorological data from Station Papa, fisheries-oceanography research in the Bering Sea, acoustic data from the Ross Sea, and analyzing e-DNA samples. The students are supported through NOAA, University of Washington’s Joint Institute for the Study of the Atmosphere and Ocean (JISAO) internship program, and Oregon State University’s Research Experience for Undergraduates.

Harrison Knapp is a NOAA Hollings Scholar working with Dr. Chidong Zhang on assessing the influence of the Madden-Julian Oscillation on snowpack in the Western United States. He is currently a student at the University of Southern California pursuing both a B.S. in GeoDesign and a B.A. in Earth Sciences.

Sam Mogen is a NOAA Hollings Scholar working with Drs. Jessica Cross and Darren Pilcher on exploring oxygen cycling in the Bering Sea using the Bering 10K model. He is a student at the University of Virginia studying environmental science and global studies.

Madeline Talebi is a JISAO intern working with Drs. Meghan Cronin and Nick Bond on finding and interpreting archived meteorological data from Station Papa Ocean Weather Ship between December 1949 and 1981. She is currently studying Chemical Engineering at the University of California, Irvine.

Isabelle Chan is a JISAO intern working on decreasing the degree of uncertainty between water vapor and carbon dioxide measurements with Dr. Sophie Chu. She is currently studying Environmental Science with an emphasis in Conservation at the University of North Carolina, Wilmington.

Leo MacLeod is a undergraduate at the University of Washington working with Dr. Carol Ladd on fisheries-oceanography research in the Bering Sea.

Ellie Lee is a JISAO intern working with Dr. Carol Stepien in the Genetics and Genomics Group.

Miriam Hauer-Jense is working with Drs. Bob Dziak and Joe Haxel  on analyzing data from the Ross Sea hydrophones for marine mammals through Oregon State University’ Research Experience for Undergraduates program. She is a sophomore at Scripps College. 

Read more about each of them and their projects here.

February 21, 2019
Research Vessel Sarmiento de Gamboa in the western Antarctic Peninsula

R/V Sarmiento de Gamboa in the western Antarctic Peninsula. Photo Credit: Rafa Abella

Hydrophone getting ready for deployment.

Hydrophone getting ready for deployment. Photo Credit: Lauren Roche

February 21, 2019

PMEL staff at the NOAA Cooperative Institute for Marine Research Studies at Oregon State University recently participated on a hydrophone deployment cruise aboard the Spanish R/V  Sarmiento de Gamboa in the Bransfield Strait off the western Antarctic Peninsula along with colleagues from the University of Washington, Woods Hole Oceanographic Institute, Queens College and the University of Granada (Spain) from January 4 - 17. PMEL successfully deployed 6 hydrophone moorings, while the University of Washington, Woods Hole and Queens College deployed 30 ocean bottom seismometers, and the University Granada deployed 20 land-based seismic stations.

The Bransfield Strait region is a highly volcanic area, with multiple, recently active, submarine and subaerial volcanoes including the active Deception Island volcano which last erupted in 1970 damaging the Spanish Antarctic base located there. Thus the goal of the project is to assess the volcanic hazard to the collection of international polar bases located in this part of Antarctica, as well as to better understand the ocean soundscape and sea-ice dynamics in the region.  Using both active and passive seismo-acoustic data collection techniques, researchers will be able to image shallow pockets of magma in the crust that are likely distributed throughout the entire area. This research is funded by the National Science Foundation Antarctica Program.

Learn more about PMEL's Acoustic Program here:


PMEL Project: 

November 29, 2018

Two blue whale spouts seen from the boat on October 17, 2018. Photo taken under NMFS permit 20465

November 29, 2018

On October 17, 2018, a joint NOAA/PMEL and Oregon State University Marine Mammal Institute (OSU-MMI) team, with the assistance of a U.S. Coast Guard helicopter on patrol providing real time radio reports of cetacean sightings, traveled 27 miles off the Oregon coast (due west of Newport, Oregon) to acquire acoustic recordings and biopsy two North Pacific blue whales. Through MMI contacts, the Coast Guard helicopter out of North Bend spotted blue whales off shore during routine patrol, and alerted the team to their approximate location.

A PMEL drifting hydrophone was used to record the blue whale calls, while OSU-MMI personnel successfully collected a biopsy sample of one of the two blue whales, and documented the encounter with photographs. Genetic results show the biopsied animal was a male, acoustic analysis of call signal strength shows two animals observed during biopsying were likely source of recorded vocalizations. The researchers are currently doing further genetic analysis and photo identification work to confirm blue whale population and gender of animals recorded. These data will be used to correlate the genetic identity and acoustic call type of a North Pacific blue whale. 

The goal is to quantify and relate call signal characteristics and genetic identity. Typically, only remote recordings of blue whale calls are used to assess population size and distribution of this endangered species.

All research was conducted under NMFS permit 20465 with the support of the Marine Mammal Institute whale telemetry group.

PMEL Project: 

June 28, 2018
A hydrophone is placed on the ocean floor to record the sound of bubbles.

A hydrophone is placed on the ocean floor to record the sound of bubbles. Photo credit: Ocean Exploration Trust

June 28, 2018

PMEL's Acoustic and Earth-Ocean Interactions programs have successfully recorded the sound of methane bubbles from the seafloor off the Oregon coast using a hydrophone, opening the door to using acoustics to identify - and perhaps quantify - this important greenhouse gas in the ocean. Methane is found both as an icy hydrate deposit and in a gas phase within the sediments of the continental margins. The methane stored in the Cascadia margin, located offshore Washington, Oregon, and northern California, is of particular interest because the methane is stored within a major subduction zone which can potentially have an environmental impact on the upper water column and possibly the atmosphere. 

In recent years, scientists have found hundreds of bubble streams emanating from methane deposits off the Pacific Northwest coast, but they have no way to determine how much methane is stored there. In 2016, researchers used the remotely operated vehicle (ROV) Hercules from the Ocean Exploration Trust's Exploration Vessel (E/V) Nautilus to deploy a hydrophone about 6 miles off Heceta Bank on the Oregon continental margin in 1,228 meters of water (about three-fourths of a mile deep). The acoustic signatures of the bubbles from the seep site are depicted in the hydrophone record as a series of short, high-frequency bursts, lasting 2-3 seconds.

"The bubbles in the streams make sound, and the frequency of the sound is related to the size of the bubble," said Robert Dziak, an acoustics scientist with the National Oceanic and Atmospheric Administration and lead author on the study. "The smaller the bubble, the higher the pitch. And the larger the bubble, the lower the sound pitch, but the more methane it contains.

The researchers then compared the sound record with still images from the ROV and found their estimates of bubble size from the hydrophone record matched the visual evidence. Results of the study have just been published in the journal Deep-Sea Research II.

On the current Nautilus research cruise mapping methane seeps, a hydrophone was deployed and recovered at various depths of Astoria Canyon in order to compare how bubble sizes and rates change with depth.

The next step, researchers say, is to fine-tune their ability to detect the acoustic signature of the bubbles so they can use the sounds to estimate the volume of methane in the offshore reservoirs. The ultimate goal is to be able to use sound to estimate the volume and rate of methane gas exiting the seafloor.

PMEL Project: