Obliquity, i.e. variations in the Earth's axial tilt, range from ________ to ________ over a 41,000-year cycle.
A) 10.5 to 24.5
B) 20.5 to 23.5
C) 11.5 to 15.5
D) 23.5 to 27.5
E) 21.5 to 24.5
Question 2
Broadly defined, the biosphere
A) only includes the biotic components of an ecosystem, with the abiotic components being considered part of the lithosphere, hydrosphere, or atmosphere, respectively.
B) extends from the ocean floor to an altitude of approximately 8 km (5 mi) into the atmosphere.
C) is more a theoretical construct than an observable sphere of study.
D) consists of only terrestrial organisms, while the hydrosphere includes aquatic and marine organisms.
E) encompasses both the lithosphere and the hydrosphere, but not the atmosphere.
A Piece of Mars on Earth
Earth’s history is divided into nested sets of time--eons, eras, periods, and epochs--and is called
Earth’s Spheres
Earth’s Spheres
Short-wavelength flux is reflected by Earth
Moving currents are affected by Earth’s rotation