What three factors affect how magma forms?
What is Jupiter's great red spot?
A cyclonic storm
What is the ring of fire?
A long belt of volcanoes that circles much of the pacific ocean.
What is the role of isotopes in radiometric dating?
A radioactive isotope decays into its stable daughter product at a constant rate. The time it takes for half of the isotope in a sample to decay is known as the half-life of the isotope. A radioactive isotope can thus serve as a "clock" that can be used to determine the age of a substance.
What causes a star to die?
A star runs out of fuel and collapses due to gravity.
What are abyssal plains? How are abyssal plains formed?
Abyssal plains are deep, extremely flat features of the ocean floor. They are formed as sediments from coastal regions are transported far out to sea and settle to the ocean floor, and as materials from the water column above settle to the bottom.
In your own words, define the principle of fossil succession and the theory of evolution.
According to the principle of fossil succession, specific groups of fossils occur in particular rock layers. Each layer differs, and changes in life forms can be observed from layer to layer. According to the theory of evolution, life forms have evolved, or changed over time, through natural selection.
Why do we not often see drawing of our solar system drawn to accurate scale?
Because the planets would be very small and difficult to see in a drawing that is set to accurate scale.
List 3 volcanic landforms.
Calderas, Volcanic necks and lava plateaus.
What factors determine the type of volcanic eruption?
Characteristics of magma (temperature and composition) and the amount of dissolved gas.
What are the sources of salt in ocean water?
Chemical weathering of rocks on continents; Earth's interior
Why is the neritic zone rich in life?
Conditions are ideal for photosynthesis because there is light and nutrients from runoff; the bottom provides shelter and habitat.
How do continental margins in the Atlantic Ocean differ from those in the Pacific Ocean?
Continental margins in the Atlantic Ocean consist of thick layers of undisturbed sediment and there is little volcanic or earthquake activity. In Pacific Ocean margins, oceanic crust is being pushed beneath continental crust, leaving narrow margins with volcanic and earthquake activity.
What types of radiation make up the electromagnetic spectrum?
Electromagnetic radiation includes rays, X-rays, ultraviolet light, visible light, infrared radiation, microwaves, and radio waves.
What three factors affect how magma forms?
Heat, pressure, water content
In your own words, write definitions of inclusion, unconformity, and correlation.
Inclusion: piece of one kind of rock contained in another rock; unconformity: surface that represents a break in the rock record; correlation: way of determining that two separated rock units came from the same time period. Often certain fossils can be helpful for matching up rock layers. Index fossils are widespread geographically for a short period of time.
What causes intraplate volcanism?
Intraplate volcanism occurs where a mass of hotter-than-normal mantle material called a mantle plume rises towards the surface. Once the plume nears the top of the mantle, decompression melting forms magma,. The result may be a small volcanic region called a hot spot.
What is the largest planet? Smallest?
Jupiter is the largest planet. Mercury is the smallest.
List the materials ejected from volcanoes.
Lava flows or pyroclastic materials.
How are gas hydrates formed?
Most oceanic gas hydrates are formed when bacteria break down organic matter trapped in seafloor sediments. The bacteria produce methane gas along with small amounts of ethane and propane. These gases combine with water in deep-ocean sediments in such a way that the gas is trapped inside a lattice-like cage of water molecules.
How are the location of volcanoes related to plate boundaries?
Most volcanoes occur along divergent and convergent plate boundaries. Some volcanoes occur far away from boundaries called hot spots.
How does the area of Earth's surface covered by the oceans compare with the area covered by land?
Nearly 71 percent of Earth's surface is covered by oceans, 29 percent is covered by land.
What is the difference between plankton and nekton?
Nekton are able to move independently of ocean currents. Plankton are not.
What is formed at mid-ocean ridges?
New ocean floor
What are the main energy resources from the ocean?
Oil and natural gas
What advantage do organisms in a food web have over those in a food chain?
Organisms in a food web have alternative foods to eat if one of their food sources diminishes or disappears.
Name the four ocean basins. Which of the four ocean basins is the largest? Which is located almost entirely in the southern hemisphere?
Pacific Ocean, Atlantic Ocean, Indian Ocean, Arctic Ocean; Pacific Ocean; Indian Ocean
What units are used to express the salinity of ocean water?
Parts per thousand
List the different types of fossils.
Petrified fossils, molds and cases, carbon films, preserved remains, and trace fossils
How is magma formed through decompression melting?
Pressure drops enough to allow melting of rock within the mantle.
What is salinity?
Salinity is the total amount of solid material dissolved in water.
Describe radiocarbon dating.
Scientists measure the ratio between the amount of radioactive isotope atoms and daughter product atoms in a substance. The ratio reflects how much time has passed since the substance formed.
How do scientists determine the elements in a star?
Scientists study the star's spectrum. The spectral lines act as "fingerprints," which identify the elements present and thus the star's chemical composition.
Explain the relationship between latitude and sea surface temperature.
Sea surface temperature is higher at the equator and low latitudes. Sea surface temperature decreases as latitude increases.
How do geologists use radiometric dating to date sedimentary rock layers indirectly?
Sedimentary rock layers that lie between two igneous rock units must have an age that lies somewhere between the absolute ages of the two igneous rock units. The latter can be dated using radiometric methods.
How are plutons classified?
Shape, size and relationship to surrounding rock layers
Describe the 3 main types of volcanoes.
Shield vocanoes are broad and formed by lava eruptions. Cinder cones are smaller, made from one time eruptions and of cinders produced from gas rich magma. Composition cones are large and made from both lava and pyroclastic materials. These can be very explosive.
List 3 different types of plutons.
Sill, laccolith, dike
What is the geologic time scale?
The geologic time scale divides Earth's history into units that each represent specific amounts of time.
List and briefly describe principles of relative dating.
The law of superposition states that in a sequence of undisturbed rock layers, the oldest layer is on the bottom; the upper layers are progressively younger. The principle of original horizontality states that sedimentary rocks are generally deposited horizontally. The principle of cross-cutting relationships states that features such as faults and intrusions are younger than the features they cut across.
What happens to atoms that are radioactive?
The nuclei decay
List three main ideas of the science of geology.
The rock record provides evidence of Earth's history. Processes at work today were also at work in the past. Earth is very old and has changed over time.
Describe the life cycle of the sun.
The sun began as a nebula, became a protostar and then a main-sequence star. It will become a red giant, planetary nebula, white dwarf, and finally a black dwarf.
How does the topography of the ocean floor compare to that on land? Name three topographic features found on the ocean floor.
The topography of the ocean floor is as diverse as that of continents. Three topographic features: mid-ocean ridges, trenches, abyssal plains.
Describe two ways that geologists can use fossils to interpret Earth's history.
To correlate rock layers and to reconstruct past environments
What are trenches? How are deep-ocean trenches formed?
Trenches are long, narrow creases in the seafloor. They are formed at convergence sites where one plate descends beneath another and plunges back into the mantle.
At what point is a star born?
about 10 million K, pressure within it is so great that nuclear fusion of hydrogen begins, and a star is born.
What factors are used to divide the ocean into marine life zones?
availability of sunlight, distance from shore, water depth
How can marine organisms be classified?
by where they live and how they move
What are the three main regions of the ocean floor?
continental margin, ocean basin floor, mid-ocean ridge
What subdivisions make up the geologic time scale?
eons, eras, periods, and epochs
How can scientists determine is a star is moving away or towards earth?
indicates that a star is moving away from Earth. A blue shift indicates that a star is moving toward Earth.
What does terrigenous sediment consist of?
mineral grains weathered from continental rocks
How is hydrogenous sediment formed.
minerals crystallize directly from the water through chemical reactions
In which area of the ocean do most benthos organisms live?
on the shallow coastal ocean floor
What drawbacks are associated with harvesting ocean resources for energy use?
possibility of oil spills, possible effects on marine habitats, gas hydrates break down quickly when brought to the surface
Describe the conditions that favor the formation of fossils.
quick burial, possession of hard parts
What other resources are derived from the ocean?
sand and gravel, evaporative salts, manganese nodules
What is the composition of biogenous sediment?
shells and skeletons of marine animals and algae
What types of technology are used to study the ocean floor?
sonar, satellites, submersibles
What factors influence a region's photosynthetic productivity?
sunlight and nutrient availability
What factors affect the density of ocean water?
temperature and salinity
What are the three types of ocean floor sediments?
terrigenous, biogenous, hydrogenous
What limits primary productivity in tropical oceans? Why?
the availability of nutrients; solar energy is available year-round but nutrients are trapped in deeper waters because the permanent thermocline prevents mixing between surface water and deeper water.
Describe the transfer efficiency between trophic levels.
very inefficient, as little as 2 percent
