Measured in degrees north or south of the equator, this angular distance can be very informative of climate at a given coordinate.
What is latitude?
100
Organisms whose metabolic pathway involves taking in sunlight and respiring oxygen in this process are responsible for contributing O2 to our atmosphere during the Precambrian.
What is photosynthesis?
100
Oceanic crust is formed primarily of this rock.
What is basalt?
100
While debated by non-scientists, the current scientific consensus is that the burning of fossil fuels are responsible for various effects of this phenomenon.
What is climate change?
100
This hypothesis states that the formation of the Solar System is the result of a protoplanetary disk revolving around the Sun.
What is the nebular hypothesis?
200
Lines of longitude are given in degrees with reference to one of these cardinal directions.
What are east and west?
200
This part of the atmosphere is made of O3, and protects Earth from lethal amounts of UV radiation.
What is the ozone layer?
200
From the Greek words for “rocky sphere,” this rigid outer layer of the Earth is composed of crust and the uppermost mantle.
What is the lithosphere?
200
The level of this property is especially high for water, which is why the human environmental impact has seemed relatively negligible to non-scientists.
What is specific heat capacity?
200
Wegener's theory of continental drift suggested that continents moved by doing this.
What is plowing through oceanic crust?
300
Before GPS, this angle-measuring instrument was commonly used to navigate.
What is a sextant?
300
Without this molecular compound, which has many special properties and covers most of Earth's surface, life on Earth would be unlikely.
What is water?
300
Continental crust primarily has this composition, which is why it is less dense than relatively iron-rich oceanic crust.
What is granitic? (Also acceptable: What is granodioritic? What is felsic?)
300
While levels of this molecular compound have been higher in the past, the combustion of fossil fuels is outpacing oceans' mitigation of the effects.
What is carbon dioxide? (Also: What is CO2?)
300
A mechanism in plate tectonic theory, evidence for this process was gathered by using magnetometers and determining the relative ages of oceanic crust.
What is seafloor spreading?
400
A person who is located 15 degrees east of the Prime Meridian experiences noon at this hour, GMT.
What is 11 am?
400
Convection in the liquid outer core of the Earth generates this, which protects the planet from an influx of vast amounts of charged particles.
What is Earth's magnetic field?
400
Despite being a solid, the asthenosphere has this physical property, which allows it to “flow.”
What is ductility?
400
While regions at these latitudes experience more variability in temperature, polar regions are currently experiencing the drastic effects of human-driven ecological damage.
What are low latitudes?
400
This process is responsible for the internal heat of the Earth, which drives plate tectonics and also provides clues to Earth's age.
What is radioactive decay?
500
This mathematician estimated the circumference of the Earth using sunbeams and vertical sticks called gnomons.
Who is Eratosthenes?
500
The lighter elements of Earth's earliest atmosphere were driven off by this.
What is solar wind?
500
Earth's core is primarily composed of this element.
What is iron? (Also acceptable: What is nickel?)
500
"Ocean acidification" is a raise in pH caused by the release of hydrogen (H+) ions, after CO2 combines with this molecular compound.
What is carbonic acid?
500
These volcanic regions which do not typically correspond to plate boundaries are hypothesized to occur due to upwelling magma from deep in Earth's mantle.