Chapter 5 (week 3)
Eutrophication: is the movement of a body of water′s trophic status in the direction of
increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and
phosphates, through fertilizers or sewage, to an aquatic system.
Cycle: shape the landscapes around us and guide the flow of key chemical elements and
compounds that support life and regulate climate.
Open system: Systems that receive inputs of both energy and matter and producer outputs of
Closed system: Systems that receive inputs and produce outputs of energy, but not matter.
Feedback loop: Sometimes a system’s output can serve as input to that same system.
Feedback loops are of two types, negative and positive.
Negative feedback loop: Output that results from a system moving in one direction acts as
input that moves the system in the other direction.
Positive feedback loop: Have the opposite effect. Rather than stabilizing a system, they
drive it further toward on extreme or another.
Homeostasis: The tendency of a system to maintain constant or stable internal condition.
Steady state: Homeostatic systems are often said to be in a stable or steady state.
Emergent properties: Characteristics nor evident in the components alone.
Lithosphere: Is the rock and sediment beneath our feet, I the planet’s uppermost layers.
Atmosphere: is composed of the air surrounding our planet.
Hydrosphere: Encompass all water, salt or fresh, liquid, ice, or vapour in surface bodies,
underground, and in the atmosphere. Biosphere: consists of the total of all the planet’s living organisms and the abiotic (nonliving)
portions of the environment with which they intersect.
Rock cycle: Rocks and minerals that compose them are heated melted, cooled, broken down,
and reassembled in a very slow process.
Manga: All rocks can melt. At high enough temperatures, rock will enter a molten, liquid sate.
Intrusive or plutonic rock (rock-granite): Magma that cools slowly and solidifies while it
is still well below Earth’s surface.
Extrusive or volcanic rock (rock-basalt): In contrast, when magma is ejected from a
volcano, it cools very quickly, so minerals have little time to grow into coarser crystals.
Sediments: Particles of rock blown by wind or washed away be water finally come to rest
downhill, downstream, or downwind from their sources.
Sedimentary rock (rock-limestone and rock-sandstone): is formed when dissolved
minerals seep through sediment layers and act as a kind of glue, called cement, which
crystallizes and binds the sediment particles together.
Lithification: is the process in which sediments compact under pressure, expel connate
fluids, and gradually become solid rock. Essentially, lithification is a process of porosity
destruction through compaction and cementation. Lithification includes all the processes
which convert unconsolidated sediments into sedimentary rocks. Petrification, though often
used as a synonym, is more specifically used to describe the replacement of organic material
by silica in the formation of fossils. In geology consolidation is a synonym for lithification.
Metamorphic rock (rock-gneiss (make up the Canadian Shield)): When
great heat or pressure is exerted on rock, the rock may change its form.
Plate tectonics: a process that underlies earthquakes and volcanoes and that
determines the geography of Earth’s surface.
Earth’s surface consists of a lightweight thin crust of rock floating atop a malleable mantle,
which in turn surrounds a molten heavy core made mostly of iron. Divergent plate boundaries: Manga surging upward to the surface divides plates and
pushes them apart, creating new crust as it cools and spreads.
Transform plate boundary: When two plates meet, the may slip and grind alongside one
another and creating fiction that spawns earthquakes along slip-strike faults.
Convergent plate boundaries: Either of two consequences may result. First, one plate of
crust may slide beneath another in a process called subduction. The subducted crust is heated
as it dives into the mantle, and it may send up magma that erupts through the surface in
Ecosystem: An ecosystem of all organism and nonliving entities that occur and interact in a
particular area at the same time.
Biomass: Organisms at higher tropic levels, transferring energy, organic material