Practice Exam Flashcards
Explain why it’s important for anyone who wants to extract minerals from the ground to understand the geothermal gradient
The geothermal gradient is important for several reasons. The geothermal gradient helps to predict temperatures at a certain depth which is important for extracting minerals - it helps you to know which equipment and drilling techniques should be used. It affects the formation and stabilization of minerals as the temperature and pressure at different depths can cause minerals to either dissolve or precipitate out of a solution. The geothermal gradient can influence the concentration and distribution of minerals. Certain minerals are more likely to be found in certain depths or temperatures. It can help minimize the environmental disruption because it allows for more accurate predictions of surface concentrations
Explain how absorption lines allow us to know what the sun is compromised of
Absorption lines allow us to know what elements are present in a star. We know that the sun is compromised of the same elements as earth, but in different proportions - hydrogen (73%) and helium (25%). Absorption lines appear in a spectrum if an absorbing material is placed between the material (the sun) and us (the observers). This material could be the outer layers of a star, a cloud of interstellar gas, or a cloud of gas. By looking at the absorption line spectrum we are able to determine what elements the sun is compromised of
Where do earthquakes happen? What are the focus and epicenter? What are some consequences?
Earthquakes are caused when underground rocks suddenly break along a fault causing seismic waves, which cause the ground to shake. Earthquakes typically occur along oceanic and continental plates. The focus is the spot underground where rocks break. The epicenter is the place right above the focus. Earthquakes pose a risk to the health, safety, and economic viability of Canada and the rest of the world. A recent example is the earthquake that hit Turkey where it resulted in massive loss of life, huge financial instability, and the downfall of industrial societies.
What is Absolute Dating and it’s 3 methods?
Absolute Dating used different methods to chronologically estimate the age of certain geologic materials in fossils and the direct age of fossils. Radiometric dating uses the radioactive decay of certain materials such as potassium and carbon, as reliable clocks to date ancient events. Electron spin resonance and thermoluminescence assess the effects of radioactivity on the accumulation of electrons of the crystal structure of a mineral to determine its age. Radioactive decay is when an unstable isotope changes its number of protons or neutrons or both
What are the Saturnian satellites and what is so special about Enceladus?
Enceladus is a small ocean world covered in ice. It’s one of 60 confirmed moons that orbit Saturn. It’s young - less than 100 million years old. A global ocean flows under an ice shell 30-40 km thick. Life could exist
Choose 2 exoplanets and discuss their characteristics
Kepler 186f was the first rocky planet to be found within the habitable zone. It’s close in size to earth. It orbits its star once every 130 days. It resides in the Kepler 186 system. It receives 1/3 of the energy from its sun-like star that earth receives from our sun. Osiris was the first planet to be seen in transit and have its light directly detected. Scientists detected oxygen and carbon in its atmosphere. It has an evaporating hydrogen atmosphere. It’s 7 million miles away from its star and has a surface heated to 1000 degrees C. It’s classified as a Chthonian planet due to its completely dead core of evaporated gas giants
What is the importance of the lithosphere and the asthenosphere in moving plate tectonics?
Plate tectonics is the theory that the earth’s outer shell is divided into several plates that glide over the mantle, the rocky inner layer of the core. These plates act like rigid hardshell compared to earth’s mantle. The outer shell is the lithosphere which is 100 km thick. The lithosphere consists of the crust and outer part of the mantle. Below the lithosphere is the asthenosphere, which is malleable or partially malleable, allowing the lithosphere to move around a bit.
Explain why the Hubble Space Telescope is important and include some facts
The Hubble space telescope orbits our planet at an altitude of 547 km. The telescope is inclined at 28.5 degrees to the equator. At this vantage point, we are able to see crystal-clear images of our planet without the atmosphere getting in the way. The telescope takes about 95 minutes to complete one full orbit around the earth. The telescope was named after Edwin Hubble, who along with another astronomer, confirmed the universe is expanding.
Explain the 5 basic characteristics of a star
Luminosity is the amount of light a star radiates. We can determine a star’s luminosity by its size and surface temperature. Apparent Magnitude is a star’s perceived brightness factoring in size and distance. Absolut Magnitude is a star’s true brightness that is determined by its distance from earth. A star’s color is determined by its surface temperature. Cooler stars tend to be redder while hotter stars tend to be bluer. Stars that are yellow have an average temperature like our sun. A star’s surface temperature is measured using the Kelvin scale. Zero degrees on the kelvin scale is theoretically absolute zero and equal to -273 degrees C. We can measure a star’s size by comparing it to our own sun. Our sun has a radius of 1 solar radii, meaning a star with that same measurement is the same size as our sun. We can also determine a star’s mass by comparing it to our own sun
How do volcanoes form?
Volcanoes usually form at the boundaries of the earth’s tectonic plates. These plates are huge slabs of the earth’s crust and upper mantle that fit together like puzzle pieces. Although the plates are not fixed in one place, they move at an extremely slow rate; only a few cm every year. The plates either collide together or move apart. Volcanoes are common in geologically active boundaries. Principle types of volcanoes include stratovolcanoes, shield volcanoes, lava domes, and pyroclastic cones.
What methods are used to detect planets?
Radial Velocity, aka Doppler Spectroscopy, was the only known method capable of detecting extrasolar planets. It relies on the fact that a star does not remain completely stationary when it is orbited by another planet. As a star moves away from us, the light waves leaving the star are stretched and move toward the red end of the spectrum. As a star moves toward us the light waves are compressed and move toward the blue end of the spectrum. Transit photometry measures the minute dimming of a star as an orbiting planet passes between it and the earth. If dimming changes, a planet is orbiting around it and passing in front of it once every orbital period. Microlensing is the only method capable of discovering planets at a truly great distance. This is an astronomical effect predicted by Einstein’s General Theory of Relativity. When the light emanating from a star passes close to another star, the gravity of the lensing star will bend the light-years of the source star causing them to appear farther apart than they actually are. If a source star passes behind an intermediary star, light rings will appear known as Einstein’s rings.
Describe the String Theory
The string theory is the best contender for a quantum theory of gravitation. It states that everything in the universe is made up of open strings with two separate ends to form a type of loop. Spatial curvature describes the way spacetime is curved due to gravity
What happened during the Pleistocene Epoch?
The Pleistocene Epoch is defined as the time period that began 2.6 million years ago until 11,700 years ago. This epoch was the most recent ice age where glaciers covered huge parts of the heart. Large sheets of ice covered all of Antarctica, large parts of Europe, North, and South America, and small parts of Asia. This epoch was the first in which Homo Sapiens evolved, and in the end, humans could be found all over the world. This epoch was followed by the current stage called the Holocene Epoch.
Who was J. Tuzo Wilson and why was he so significant?
J. Tuzo Wilson, a Canadian geophysicist, had a theory on why some volcanoes appear thousands of km away from tectonic plate boundaries which is where they usually occur, In 1963, he stated that these volcanoes are created by exceptionally hot areas fixed deep below the mantle. These hot spots can independently melt the plate directly above them, creating magma, which erupts onto the top of the plate. Hot spots beneath the ocean create volcanic mounds. These mounds, over millions of years, grow until they reach sea level and creates volcanic islands.
What is Hubble Law? What are some objectives of the Hubble Space Telescope?
Hubble’s Law states that the redshifts in the spectra of distant galaxies are proportional to their distance. Hubble’s objectives are to study the history and evolution of the universe, confirm the universe’s physical laws, investigate the constitution, physical characteristics, and dynamics of celestial bodies, and provide a long-term space research facility for optical astronomy.
Explain what Precambrian Time was like and the features of that time.
Precambrian time began 4.6 million years ago and until 541 million years, known as the beginning of the Cambrian period. Several rock types indicated the type of environments that could have existed during this time. Precambrian rocks contained evidence of the very beginnings of life on earth, nearly 3.5 million years ago. This time is known for the explosion of life forms without skeletons and the development of sexual reproduction. It’s divided into the Archean and Proterozoic Eons.
What are the 6-8 qualities of water that make it unique? Explain how it fully functions on Earth
Our earth is the only known planet with huge bodies of liquid water. Water is unique in that it can absorb enormous amounts of water without a large alteration in its temperature. During the day, water absorbs enormous amounts of heat in order for the earth to stay cool. During the night, water releases the heat it absorbed during the day in order to keep the surface from freezing solid. Compared to virtually all other materials, water contracts when it is cooled and then expands until it freezes. The Coriolis effect which produces ocean currents, keeps the ocean in liquid form so the myriad of creatures can thrive.
What are the Galilean Satellites and what is so special about Europa?
Europa’s surface is mostly water and ice, but beneath the ice, the crust is liquid water. Europa’s ice crust is 15-25 km thick. Europa orbits Jupiter every 3.5 days. There is a potential for life such as cells and microbes - but not humans because the atmosphere is too thin.
