History of Earth
What life-sustaining gas was lacking in the earliest atmosphere until photosynthetic organisms evolved?
Oxygen
Which lines run parallel to the equator and indicate north-south position?
Lines of latitude
In a light wave, what is the distance from peak to peak?
Wavelength
How does ocean depth affect light absorbance?
More depth = more absorbance
What is sonar used for?
Visualizing the seafloor
What's the name of the supercontinent that broke up 175 million years ago, creating ocean basins where none existed before?
Pangaea
In what environment did earliest life on Earth form?
Oceans
In a wave of light, what is the distance from peak to midpoint (the height of the wave)?
Amplitude
In A = E*c*l, what does l represent?
Path length (of light)
What is another word for biosonar?
Echolocation
What gas, lacking in the early atmosphere, now provides UV protection for organisms on Earth's surface?
Ozone
What is the name for the giant irregular plates that divide Earth's crust?
Tectonic plates
In a wave of light, what is number of waves that pass through a given point per unit of time?
Frequency
In A = E*c*l, what does c represent?
Concentration (of solute)
Where is sonar tech usually operated from?
Surface vessels
What is the current estimated age of the Earth?
4.6 billion years
Name one of the two main early sources of water
Steam from volcanic eruptions OR water released from comets that struck Earth
How deeply does light penetrate ocean water?
5-200 m, depending on turbidity
In A = E*c*l, what does E represent?
Molar absorptivity
What type of sonar uses overlapping sound transmitters and receivers to produce a higher-resolution image than traditional sonar?
Multibeam sonar
What's the term for the "explosion" of life that occurred during the Cambrian period, 542-488 million years ago?
Cambrian explosion
What's the term for the process of tectonic plates moving apart, forming new ocean crust?
Seafloor spreading
Which property determines what we perceive as color?
Wavelength
What is the name of the instrument used to measure light absorbance?
Spectrophotometer
What does sonar stand for?
SOund NAvigating Ranging systems