SCIENCEEEE

• A volcano is an opening in the earth's surface through which hot gases, ash, and molten rock are ejected from the earth's interior
• Structure of a volcano:

  • Vent: central feature of a volcano through which gases, ash, and rock are ejected
  • Magma: molten rock beneath the earth's surface
  • Magma chamber: reservoir of magma, above ground structure built from lava
  • Cone: bowl-shaped depression surrounding the vent, often caps the cone
  • Crater: a bowl- or funnel-shaped depression that usually lies directly above the vent from which volcanic material is ejected.
• Types of volcanoes:

  1. Cinder cones: consists primarily of erupted volcanic ash and rock fragments called cinders

  • Example: Mt. Ngauruhoe, New Zealand

  2. Mild Eruption: Mauna Loa, Mauna Kea

  • Examples of composite volcanoes or stratovolcanoes

  3. Symmetrical, wide-based mountains: Mount Fuji, Mount St. Helens
• Types based on volcanic activity:

  • Active Volcano: has erupted within recorded history, currently producing seismic activity
  • Dormant Volcano: inactive volcano that could erupt again
  • Extinct Volcano: probably not erupt again
• Causes of volcanic eruption:

  • For an eruption to occur, enough magma must accumulate in the chamber under the volcano
  • Triggers for eruption could be injection of new magma, buildup of gases, or a landslide
  • Effusive eruption: outpouring basaltic magma that is relatively low in viscosity and gas content
  • Explosive eruption: magma that is more viscous and has a higher gas content, with types like Plinian, Vulcanian, Icelandic, Pelean, Hawaiian, Strombolian
• Ejecta from volcanic eruptions may include:

  1. Gaseous ejecta: poisonous gas near the vent, 60% gases consist of water vapor, CO2, Cl, SO2, H2, CO, N, HCl

  2. Liquid ejecta: lava with three kinds - Pahoehoe, Aa, Pillow lava

  3. Solid ejecta: pyroclasts, particles or blocks of solid volcanic ejecta like volcanic ash, lapilli, volcanic blocks, volcanic bombs
• Volcanic structures:

  • Caldera: huge bowl-shaped craters
  • Lava tunnels
  • Igneous intrusion
• Location of volcanoes:

  • Three main belts: Ring of Fire, Alpide belt, Mid-Atlantic Ridge
• Earthquakes are caused by the sudden movement of rock masses along a fault
• There are three types of faults:

  • Normal Fault: occurs when rocks along one side of a fault sink vertically, often resulting in cliffs
  • Strike-Slip Fault: occurs when rocks along one side of a fault move horizontally along the fault
  • Thrust (Reverse) Fault: results when rocks on one side of a fault are shoved on top of the rocks on the other side
• The point at which an earthquake begins is called the focus, and the epicenter is the point on the earth's surface directly above the focus
• Seismic waves are waves of energy caused by the sudden breaking of rock within the earth or an explosion. There are three types of waves: P waves, S waves, and Surface waves
• Seismographs are instruments used to record the motion of the ground during an earthquake. They are part of a seismographic network installed throughout the world
• The most active earthquake zones are the Circum-Pacific belt and the Alpide belt

  • Circum-Pacific belt includes South America, Japan, Philippines, Islands in the South Pacific, New Zealand, North America, and Central America
  • Alpide belt includes Indonesia, Northern Africa, Southern Europe, and Asia
• Intensity of earthquakes is measured by the extent of damage to properties and its effect on humans
• Magnitude describes the amount of energy released at the focus, measured on the Richter scale or the Moment Magnitude Scale
• Biotechnology is the application of biological concepts to produce products that benefit humans
• Biotechnology was coined in the 1970s when the first genetically engineered bacteria were reported
• Biotechnology is often associated with genetic engineering, specifically in the development of genetically engineered microorganisms
• Modifications of plant and animal characteristics can also be classified as parts of biotechnology
• Genetic engineering is the direct modification of an organism's genome, which is the list of specific traits (genes) stored in the DNA
• Changing the genome enables engineers to give desirable properties to different organisms
• Organisms created by genetic engineering are called genetically modified organisms (GMOs)
• DNA is deoxyribonucleic acid, a large biomolecule that contains the complete genetic information for an organism
• Every cell of living organisms and many viruses contain DNA
• The basic building block of a DNA molecule is called a nucleotide, and a single strand of DNA may contain billions of nucleotides
• A genome is the complete set of genetic information in an organism, stored in long molecules of DNA called chromosomes
• Recombinant DNA refers to DNA to which a section has been removed and replaced with a new sequence
• It also refers to the insertion of a DNA segment into another DNA to produce a hybrid gene
• CRISPR is a technology that research scientists use to selectively modify the DNA of living organisms
• History of GMO Development:

  • 1973: created first genetically modified bacteria
  • 1974: created GM mice
  • 1982: first commercial development of GMOs (insulin-producing bacteria)
  • 1994: began to sell genetically modified food
  • 2003: began to sell GMOs as pets (Glofish)
• Genetic modification can be completed by various methods:

  • Inserting new genetic material randomly or in targeted locations
  • Direct replacement of genes (recombination)
  • Removal of genes
  • Mutation of existing genes
• GMO Bacteria:

  • Bacteria are common GMOs due to their simple structure allowing easy DNA manipulation
  • Modified bacteria can produce hydrocarbons (plastics and fuels) usually found in fossil fuels
• Genetically Modified Crops:

  • Examples include Bt-corn, which produces a protein poisonous to certain insects but not humans
  • GMO crop production in the US (2010): 93% of soybeans, 93% of cotton, 86% of corn, 95% of sugar beets
• Engineering Animals:

  • Genetic engineering is applied in breeding farm animals with improved characteristics
  • Growth hormones are used to increase milk production in cows
• Bioluminescent Animals:

  • Uses include protein tracking, disease detection, and novelty pets like Glofish
  • Dolly, the first cloned sheep, was created from an adult non-reproductive cell
• Other Reasons to Genetically Modify Crops:

  • Insect resistant
  • Herbicide resistant
  • Drought/freeze resistant
  • Disease resistant
  • Faster growth
  • Improved nutrition, taste, texture, color, and size
  • Longer shelf life
• GMO Concerns:

  • Risk to human health
  • Harm to the environment and wildlife
  • Increased pesticide and herbicide use
  • Concerns about genetic engineering in humans
• Bioremediation:

  • Refers to the use of biotechnology to solve environmental problems
  • Uses natural and recombinant microorganisms to break down toxic and hazardous substances in the environment
• Plate tectonics is a scientific theory that explains how major landforms are created as a result of Earth’s subterranean movements