Final Flashcards
What is pore space in geology?
Geologists call it pore space. Similar to holes in a sponge, pore space is the empty space between particles of sand and sediment or the space within and between rocks.
Porosity
Primary porosity is the original porosity of the rock when it formed, and secondary porosity is the pore space created by subsequent processes such as fracturing.
Permeability
a measure of the ability of a material (such as rocks) to transmit fluids
Aquifer
Unconfined aquifers are where the rock is directly open at the surface of the ground and groundwater is directly recharged, for example by rainfall or snow melt. Confined aquifers are where thick deposits overly the aquifer and confine it from the Earth’s surface or other rocks.
Aquitard
any geological formation of a rather semipervious nature that transmits water at slower rates than an aquifer
Water Table
an underground boundary between the soil surface and the area where groundwater saturates spaces between sediments and cracks in rock
Hydraulic Head
the mechanical energy per unit weight of groundwater. Groundwater flows from positions of high hydraulic head to positions of lower head. The rate of flow is proportional to the rate at which head decreases with distance along the path from high head to low
Recharge
the place where water is able to seep into the ground and refill an aquifer because no confining layer is present
Discharge
the volume of water moving down a stream or river per unit of time
Artesian Well
well from which water flows under natural pressure without pumping
Potentiometric surface
A hypothetical surface representing the level to which groundwater would rise if not trapped in a confined aquifer
Cone of depression
Pumping from a well in a water table aquifer lowers the water table near the well
Saltwater (saline) intrusion
If too much freshwater is pumped from the aquifer system, then saltwater can migrate landward by a process referred to as “saltwater intrusion.
Pore collapse
a drastic, irreversible reduction in porosity due to the increase in effective stress on the rock matrix as a consequence of withdrawal of oil and gas
Subsidence
sinking of the ground because of underground material movement
Groundwater flow reversal
part of streamflow that has infiltrated the ground, entered the phreatic zone, and has been (or is at a particular time) discharged into a stream channel or springs; and seepage water
Point source / non-point source pollution
There are two categories of water pollution: Point source pollution is pollution where the source of the pollution can be identified, such as a spill or discharge. Non-point source pollution is when the source of pollution either cannot be identified or may come from many sources.
Ogallala Aquifer
The Ogallala Aquifer is a shallow water table aquifer surrounded by sand, silt, clay, and gravel located beneath the Great Plains in the United States.
Glaciers
A slowly moving mass or river of ice formed by the accumulation and compaction of snow on mountains or near the poles.
Mountain (alpine) glacier
An alpine glacier is a glacier that forms at high elevations within mountains. These glaciers flow down mountains and carve wide, ‘U’-shaped valleys.
Continental glacier
A continuous sheet of land ice that covers a very large area and moves outward in many directions.
Plastic vs Brittle
Brittle deformation may be described as structural cracking without shape change of the individual broken pieces, whereas plastic deformation is described as shape change without breakage.
Zone of accumulation
The accumulation zone is also defined as the part of a glacier’s surface, usually at higher elevations, on which there is net accumulation of snow, which subsequently turns into firn and then glacier ice.
Zone of ablation
Ablation zone or ablation area refers to the low-altitude area of a glacier or ice sheet below firn with a net loss in ice mass due to melting, sublimation, evaporation, ice calving, aeolian processes like blowing snow, avalanche, and any other ablation.
Zone of Ablation
Ablation zone or ablation area refers to the low-altitude area of a glacier or ice sheet below firn with a net loss in ice mass due to melting, sublimation, evaporation, ice calving, aeolian processes like blowing snow, avalanche, and any other ablation.
Ablation
reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches
Equilibrium line
marks the boundary between the zones of accumulation (above) and ablation (below)
Toe
the bottom, or baseline section, of the soil mass comprising the slope.
Toe
the bottom, or baseline section, of the soil mass comprising the slope.
Glacial advance/retreat
If more snow and ice are added than are lost through melting, calving, or evaporation, glaciers will advance. If less snow and ice are added than are lost, glaciers will retreat
Glacial plucking
Plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the weathering and erosion of pieces of bedrock, especially large “joint blocks”. This occurs in a type of glacier called a “valley glacier”.
Glacial abrasion
the surface wear achieved by individual clasts, or rocks of various sizes, contained within ice or by subglacial sediment as the glacier slides over bedrock.
U-shaped valley
U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom.
*Moraine (lateral, end, terminal)
Lateral Moraines: These are mounds of debris that are found along the sides of a glacier and are formed by the accumulation of material that falls off the sides of the glacier. Terminal Moraines: Terminal moraines are mounds of debris that mark the furthest extent of a glacier.
*Glacial till
the sediment deposited by a glacier
*Glacial outwash
outwash, deposit of sand and gravel carried by running water from the melting ice of a glacier and laid down in stratified deposits
Varve
successive layers of fine sediments deposited by meltwater streams into glacial lakes. During the summer months when discharge is higher, more sediments flow into the lake and deposits accumulate more rapidly.
Weather vs climate
Weather reflects short-term conditions of the atmosphere while climate is the average daily weather for an extended period of time at a certain location.
Paleoclimate
Paleoclimate research uses geologic and biologic evidence (climate proxies) preserved in sediments, rocks, tree rings, corals, ice sheets and other climate archives to reconstruct past climate in terrestrial and aquatic environments around the world.
Paleontological evidence
Paleontological resources, or fossils, are any evidence of past life preserved in geologic context. They are a tangible connection to life, landscapes, and climates of the past. They show us how life, landscapes, and climate have changed over time and how living things responded to those changes.
Sedimentological evidence
Sedimentology is the study of sediment grains in marine and other deposits, with a focus on physical properties and the processes which form a deposit.
Isotopic evidence
Isotope evidence is a powerful tool for reconstructing past human diets and subsistence adaptations (1–3), and it has been applied to a number of Neanderthals and early modern humans from Europe (4–12).
Oxygen isotopes
Periodic Table–Oxygen. Oxygen has three stable isotopes: 16O (99.63%), 17O (0.0375%) and 18O (0.1995).
Glacial / interglacial
We call times with large ice sheets “glacial periods” (or ice ages) and times without large ice sheets “interglacial periods.”
Milankovitch cycles
The Milankovitch cycles include: The shape of Earth’s orbit, known as eccentricity; The angle Earth’s axis is tilted with respect to Earth’s orbital plane, known as obliquity; and. The direction Earth’s axis of rotation is pointed, known as precession.
*Feedback (positive & negative)
Feedback loops come in two flavors: positive and negative. A negative feedback loop reduces the effect of change and helps maintain balance. A positive feedback loop increases the effect of the change and produces instability.
Greenhouse effect
The greenhouse effect is the process through which heat is trapped near Earth’s surface by substances known as ‘greenhouse gases.’ Imagine these gases as a cozy blanket enveloping our planet, helping to maintain a warmer temperature than it would have otherwise.
Greenhouse gas
Greenhouse gases (also known as GHGs) are gases in the earth’s atmosphere that trap heat. During the day, the sun shines through the atmosphere, warming the earth’s surface. At night the earth’s surface cools, releasing heat back into the air. But some of the heat is trapped by the greenhouse gases in the atmosphere.
*Keeling curve
The Keeling Curve is a graph that represents the concentration of carbon dioxide (CO2) in Earth’s atmosphere since 1958. The Keeling Curve is named after its creator, Dr.
*Carbon cycle
The carbon cycle is nature’s way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again. Most carbon is stored in rocks and sediments, while the rest is stored in the ocean, atmosphere, and living organisms.
