About Chris Knowlton

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So far Chris Knowlton has created 9 blog entries.

Glacial Calving in the Arctic Produces Record Source Levels

Iceberg calving is a natural process, occurring when a rift opens in the edge of a glacier, caused by wind or water erosion, melting ice, or other events, resulting in an iceberg breaking away and falling into the ocean. The rate at which icebergs calve from glaciers increases with increased air and water temperatures. Polar [...]

Glacial Calving in the Arctic Produces Record Source Levels2022-03-15T16:20:42-05:00

Seafloor exploration with fin whale calls

Illustration of a seismic survey with two ships, one with the sound source and the other with an array of hydrophones. Image Credit: DOSITS. At the bottom of the ocean, there are layers of sediments that contain information about the Earth’s history and below the sediment are layers of the ocean crust.  Seismic [...]

Seafloor exploration with fin whale calls2021-10-06T12:27:46-05:00

Hot Topic – Sound waves from earthquakes can reveal changes in ocean temperature

Background One of the ocean’s response to global climate change is a rise in average water temperature. Where in the ocean the warming occurs and the rate at which it occurs are of great interest to climatologists. Measuring ocean temperature to monitor and understand changes due to climate change presents some challenges because: • The [...]

Hot Topic – Sound waves from earthquakes can reveal changes in ocean temperature2021-02-15T09:27:23-05:00

Hot Topic – Listening to Monterey Bay

Hydrophone Provides Continuous, Live Stream of Deep Sea Sounds from Monterey Bay Location of the MARS hydrophone, on the Smooth Ridge, at the edge of Monterey Canyon, approximately 30 km (18 mi) from shore. Image credit: MBARI. The Monterey Accelerated Research System (MARS) cabled observatory, the first cabled oceanographic observatory on the U.S. [...]

Hot Topic – Listening to Monterey Bay2022-02-16T11:10:05-05:00

Hot Topic – Guidance on Determining Potential Effects to Marine Mammal Hearing

The National Marine Fisheries Service (NMFS) is the U.S. federal agency that is responsible for the stewardship of the nation’s ocean resources, including the management of the majority of marine mammals, such as whales, dolphins, porpoises, seals, and sea lions. The U.S. Fish and Wildlife Service (USFWS) has jurisdiction over walruses, polar bears, manatees, dugongs, and sea [...]

Hot Topic – Guidance on Determining Potential Effects to Marine Mammal Hearing2022-06-01T13:31:52-05:00

Hot Topic – Monitoring Wind Farm Construction

Monitoring the Construction of the First U.S. Offshore Wind Farm for Potential Noise Impacts on Marine Life Scientists deploy a hydrophone array to monitor the noise from construction of wind turbines of the coast of Block Island, Rhode Island. Photo credit: Jim Miller. Wind energy is increasingly being used as an alternative energy source. Winds [...]

Hot Topic – Monitoring Wind Farm Construction2019-06-19T07:09:08-05:00

Hot Topic – Hearing Sensitivity

False killer whales can lower their hearing sensitivity A recent paper by Paul Nachtigall and Alexander Supin describes how a false killer whale is able to lower its hearing sensitivity before a loud sound when given a warning beforehand. Because many marine animals depend on their hearing for feeding and communication, loud sounds in the environment can have an impact [...]

Hot Topic – Hearing Sensitivity2020-10-06T13:20:04-05:00

Hot Topic- Ocean-Based Renewable Energy

Ocean-Based Renewable Energy The European Union (EU) has committed to producing 20% of its energy from renewable sources by 2020. This has led countries such as Sweden, Ireland, Germany, and Denmark to be pioneers in developing a variety of technologies to harness and deliver energy. Systems associated with winds, waves, and tides produce underwater noise, the effects [...]

Hot Topic- Ocean-Based Renewable Energy2020-01-08T12:05:18-05:00

Hot Topic – Mass Stranding

Mass Strandings The term stranding refers to an aquatic animal observed in an inappropriate location, for example, an offshore species found inshore. Most often, stranded animals are found on a beach or in shallow water. Along the U.S. coast alone, about 1,000 cetaceans and 2,500 pinnipeds strand annually. When three or more animals strand together in time [...]

Hot Topic – Mass Stranding2018-12-19T09:19:38-05:00
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