The Moon, The Sun and Tides
Renowned oceanographer and geophysicist Walter Munk talks about the relative roles of the Sun and the Moon in tidal processes. He observes that, over time, the Moon is moving further away from the Earth. While the gravitational impact of the Moon is...
Survivors: Survival in the Intertidal Zone
Perhaps nowhere on Earth is the ability to survive better demonstrated than that part of the shore alternately exposed and submerged by tides-a region known as the intertidal zone. Remarkably, marine organisms there have evolved a multitude of ways ...
The Dynamic Theory of the Tides
Renowned oceanographer and geophysicist Walter Munk talks about the dynamic theory of the tides, noting that Sir Isaac Newton's theory of the tides was incomplete. French scientist Pierre-Simon Laplace explained a century after Newton that tidal for...
Temperature and the Velocity of Sound
Renowned oceanographer and geophysicist Walter Munk talks about the relationship between temperature and the velocity of sound, observing that velocity increases with temperature. Because temperature generally increases anywhere from ten to twenty d...
Survivors: Long-Term Survivors
Despite the challenges of long-term survival on Earth, some phyla-including sponges, jellyfish, arthropods and mollusks-have endured for hundreds of millions of years, even in the most extreme environments.
Survivors: Early Invertebrates
The first animals on Earth were invertebrates-animals without backbones-and they diversified rapidly in the geologic period known as the Cambrian.
Treasure Trove: Fishing and Regulatory Agencies
In recent years, the relationship between fishermen and regulatory agencies has grown strained as the government agencies have had to impose increasingly strict rules and regulations.
Treasure Trove: Marine Resources and Pharmaceutical Products
Among the most intriguing of all marine resources are those that have potential pharmaceutical applications. While there are significant challenges involved in harvesting marine resources for medical use, the potential for improving and even saving ...
Treasure Trove: Marine Sanctuaries
In large part to counter problems caused by overfishing, marine sanctuaries have been established at various points along United States coastlines. The concept behind these marine protected areas is much like that of a national park or wilderness re...
Shadow Zones
Renowned oceanographer and geophysicist Walter Munk talks about shadow zones, which develop in response to surface heating and other geophysical phenomena, and behind which the volume of sound is much lower than in surrounding areas.