On the Air: October 26, 2014
Graph of internal wave in the open ocean. Credit: National Oceanic and Atmospheric Administration

Waves as tall as skyscrapers ripple through the world’s oceans. They don’t come crashing ashore, though, because they travel across the ocean floor, not the surface. In fact, their effect on the surface is almost nil. But their effects on the deep ocean are critical.

Internal ocean waves are made possible by the fact that not all ocean water is the same. Water at the bottom is generally colder and denser than water near the surface.

In Print: October 1, 2014
Sand tiger sharks are predators even before they are born. Credit: Tara Haelle, www.tarahaelle.com

Survival of the fittest has been a law of nature since the beginning of life, but sometimes that struggle begins earlier than we might think. For baby sand tiger sharks, the fight literally begins even before they are born.

The female sand tiger has two wombs, but she does not have litters twice as large as other sharks. In fact, she only gives birth to two particularly strong, feisty pups. Newborn sand tiger sharks have keen eyesight and sharp teeth that have already tasted the blood of their siblings – or half siblings.