Week 4 Flashcards
How was the Sun made?
The solar system began as a huge cloud of gas and dust floating in space. This cloud, was mostly made of hydrogen and helium, with traces of heavier elements.
At some point, something (like a nearby supernova explosion) disturbed the solar nebula, causing parts of it to become denser. These denser regions began to collapse under their own gravity, pulling in more gas and dust.
As the gas and dust collapsed, most of the material was drawn toward the center, forming a protostar. This was an early, dense version of the Sun. As more gas and dust fell in, the core of the protostar became hotter and denser.
Nuclear fusion begins. When the core became hot enough (around 10 million degrees Celsius), nuclear fusion started. Hydrogen atoms began to fuse into helium, releasing huge amounts of energy.
Once nuclear fusion was steady, the Sun reached a stable state, shining brightly as it does today. The leftover material around the Sun formed a rotating disk, from which the planets, moons, and other objects in the solar system eventually formed.
What is solar nebula?
A solar nebula is the giant cloud of gas and dust from which a solar system forms.
How are gas clouds formed?
The basic materials for gas clouds come from the Big Bang, which created hydrogen and helium in vast amounts. As the early universe expanded and cooled, these gases began to clump together under the force of gravity.
What is a Planetary Nebula
A planetary nebula is a region of cosmic gas and dust formed from the cast-off outer layers of a dying star. Planetary Nebula typically a star similar in mass to our Sun.
What is the Heavy Bombardment Era?
The Heavy Bombardment Era, also known as the Late Heavy Bombardment (LHB), refers to a period in the early solar system’s history, approximately between 3.8 and 4.1 billion years ago. This era was characterized by a significant increase in the frequency of asteroid and comet impacts on the terrestrial planets, including Earth, the Moon.
The Moon’s craters is especially marked by this bombardment, and the dating of lunar rocks (Methods used to determine the age of rocks collected from the Moon).
All Solar System bodies
went through the late heavy
bombardment stage.
What is the Earth’s interior?
Crust: Thin, solid outer layer (where we live). It is where we live and is the source of soil, water, and many natural resources.
Mantle: Thick layer of solid rock that flows slowly (drives plate tectonics). Re
Inner Core: Solid, hot center made mainly of iron (under extreme pressure).
Together, these layers make up the structure of the Earth, each playing a crucial role in its geology and the processes that shape the planet.
How did the formation of Earth begin?
Earth formed about 4.5 billion years ago from the solar nebula, a cloud of gas and dust. Particles began to stick together, gradually forming a larger body that eventually became the Earth.
Heat Generation:
During Earth’s formation, intense heat was generated from several sources:
Kinetic energy from the collisions of particles.
Gravitational compression as the Earth grew larger.
Radioactive decay of unstable isotopes like uranium, thorium, and potassium.
This heat caused the early Earth to become partially or fully molten. In this molten state, the process of differentiation began.
Differentiation is the process by which a planet separates into different layers based on the density of materials.
Heavier elements, such as iron and nickel, sank toward the center of the Earth, forming the core.
Lighter elements, such as silicon, oxygen, and aluminum, rose to form the mantle and crust.
What is Differentiation?
Differentiation is the process by which a planet separates into different layers based on the density of materials.
Heavier elements, such as iron and nickel, sank toward the center of the Earth, forming the core due to gravity.
Lighter elements, such as silicon, oxygen, and aluminum, rose to form the mantle and crust. The lighter elements didn’t sink to the center of the Earth; instead, they remained near the surface due to their light mass.
What are the Plprocesses caused by Earth’s Interior Heat
Volcanism: Release of gases trapped in
the interior & extrusion of igneous rocks.
Plate tectonics: Movement and recycling
of rocks and a climate thermo-regulator.
Magnetic field: Shielding of the
atmosphere from cosmic energetic
particles.
How does the heat from earth’s interior affect Plate tectonics?
Heat from the Earth’s core and radioactive decay warms the mantle. This heat causes the rocks in the mantle to flow slowly.
The heat creates convection currents in the mantle, where hot rocks rise, cool down, and then sink back down. When the rocks in the mantle get heated by the Earth’s core, they become less dense and rise toward the surface. The rocks in the mantle moving up and down create a circular motion . This continuous cycle causes the mantle material to move. The crust moves along the mantle, driven by the convection currents in the mantle below.
The circular motion of the rocks in the mantle push and pull the tectonic plates on the surface (ex. islands), causing them to move in various ways:
Diverging (pulling apart) at mid-ocean ridges.
Converging (colliding) to form mountains or cause earthquakes.
Transform (sliding past each other), which can lead to earthquakes.
The movement of the tectonic plates leads to geological phenomena such as:
Mountain formation when plates collide.
Earthquakes when plates get stuck and suddenly shift.
Volcanoes where magma rises due to plate movements.
The internal heat of the Earth causes the mantle to move, which in turn drives the movement of tectonic plates on the surface, leading to various geological changes.
How does the heat from earth’s interior affect Volcanism?
The heat from Earth’s interior is crucial for volcanism. It originates from radioactive decay, residual heat from the Earth’s formation, and increased pressure at depth. This heat melts rocks in the mantle, forming magma, which rises due to its lower density. Ongoing heat from the Earth’s interior can cause more rock to melt into magma over time, leading to an increase in the volume of magma. leading to pressure buildup. When this pressure is released, it results in volcanic eruptions, releasing gases, ash, and lava through the cracks or weak areas of the crust. Over time, volcanic activity shapes landforms, alters climates, and impacts the atmosphere.
How does the heat from earth’s interior affect Magnetic Field?
The heat from Earth’s interior keeps the outer core molten and moving, which creates convection currents in the liquid iron and nickel. These moving currents generate electric currents, which in turn produce the Earth’s magnetic field. Without this heat, the movement in the core would stop, and the magnetic field would weaken or disappear.
How was the earth’s Atmosphere formed?
Earth’s atmosphere formed in stages: initially, a thin atmosphere of hydrogen and helium was lost to space. Volcanic eruptions then released gases like water vapor and carbon dioxide, creating a new atmosphere. As the Earth cooled, water vapor condensed into oceans, and early life forms began producing oxygen through photosynthesis. Over time, this led to the oxygen-rich atmosphere we have today, composed mainly of nitrogen and oxygen.
Why are there no plate tectonics on other planets?
Other planets don’t have plate tectonics like Earth because they lack certain conditions. Earth has enough internal heat, water, and a flexible mantle that allow its plates to move. Other planets are smaller, cooler, and don’t have enough water or the right surface conditions to support tectonic activity. Their crusts and geological histories are also different, which prevents plates from moving like they do on Earth.
Size matters because a larger planet, like Earth, retains more internal heat over time.
What is the CO2 cycle?
The CO2 cycle, or carbon cycle, refers to the movement of carbon, primarily in the form of carbon dioxide (CO2), through different parts of the Earth’s system: the atmosphere, oceans, land, and living organisms. It’s a vital process that regulates the amount of carbon dioxide in the atmosphere, which influences the Earth’s climate.
What is Sedimentary strata and how are they used to determine the age of rock?
Sedimentary strata (rock layers) help determine the relative age of rock formations and fossils through several key principles:
Law of Superposition: In undisturbed layers, the oldest layer is at the bottom, and the youngest is at the top, helping to establish the sequence of events.
