Chapter 1 - General Geology Flashcards
The science of the earth
Geology
The application of the geological sciences to engineering study for the purpose of assuring that the geological factors regarding the location, design, construction, operation, and maintenance of engineering works are recognized and accounted for.
Engineering Geology
- All engineering works are built in or on the ground;
- The ground will always, in some manner, react to the construction of the engineering work; and
- The reaction of the ground (its “engineering behavior”) to the particular engineering work must be accommodated by that work.
Philosophy of Engineering Geology
different physical features of the earth
Phyiscal Geology
study of rocks
Petrology
study of minerals
Mineralogy
formation and classification of geological structures
Structural Geology
study of earth’s history through sedimentary rocks
Historical Geology
study of remnants of ancient life (fossils)
Paleontology
Economic mineral’s formation, properties etc.
Economic Geology
Allied Branches of Geology
Engineering Geology
Mining Geology
Geophysics
Geohydrology
Geochemistry
Distance of Earth to the Sun
150 Million kilometres
The largest of several rocky planets in our Solar System.
Earth
Pole-to-pole distance of the earth
12, 714 km
Distance along equator
12, 756 km
The birth of the Sun grew by the collapse of a slowly rotating interstellar cloud of gas (mostly hydrogen) and dust. This cloud is referred to as the ______.
Solar Nebula
Layers of the Earth
Crust
Mantle
Core
The process that changes solid rock into sediments. The rock is disintegrated into smaller pieces.
Weathering
The process that moves the sediments away from their original position. These are caused by water, wind, glaciers, and gravity.
Erosion
While plate tectonics forces work to build huge mountains and other landscapes, the forces of weathering and mass wasting gradually wear those rocks and landscapes away.
Denudation
Also called physical weathering, breaks the rock into smaller pieces. The rock has changed physically without changing its composition. The smaller pieces have the same minerals, in just the same proportions as the original rock
Mechanical Weathering
Also called freeze-thaw weathering, is the main form of mechanical weathering in any climate that regularly cycles above and below the freezing point
Ice Wedging
Another form of mechanical weathering. In this, one rock bumps against another rock.
Abrasion
Different from mechanical weathering because the rock changes, not just in the size of pieces, but in composition. This works through chemical reactions that cause changes in the minerals.
Chemical Weathering
The most important agent of chemical weathering. Two other important agents of chemical weathering are carbon dioxide and oxygen.
Water
The name of the chemical reaction between a chemical compound and water. When this reaction takes place, water dissolves ions from the mineral and carries them away. These elements have undergone leaching.
Hydrolysis
These are weak acids that form when Carbon dioxide (CO2) combines with water as raindrops fall through the atmosphere.
Carbonic Acid
A chemical reaction that takes place when oxygen reacts with another element.
Oxidation
The two main components of acid rain, accelerate chemical weathering.
Sulfuric and nitric acids
Influences Weathering
Climate and Rock / Mineral type
Occurs when loose, water-saturated sediment begins to compact causing the ground surface to collapse.
Subsidence
Occurs when the water within the sediment is slowly squeezed out because of overlying weight
Slow Subsidence
Occurs when naturally acidic water begins to dissolve limestone rock to form a network of water-filled underground caverns.
Fast Subsidence
If droughts or pumping of groundwater reduces the water table below the level of the caves, these caverns collapse creating ______.
Surface Sinkhole
Stages of Stream Development
Zone 1 - Headwaters
Zone 2 - Transfer Zone
Zone 3 - Depositional Zone
Headwaters stream swiftly flow down steep mountain slopes and cut deep, v-shaped valleys. Waterfall and rapid occur in this zone.
Zone 1
Lower-elevation streams merge to flow down a gentle slope. Valleys broaden as coalescing rivers start to meander.
Zone 2
At the lowest elevations, a riven meanders across a broad, nearly flat valley and floodplain. At a river’s mouth, it may divide into separate channels as it flows across a delta extending out to the sea. The coastal plain and delta are made of river sediments.
Zone 3
This happens when two blocks of the earth suddenly slip past one another.
Earthquake
The surface where the surface of the earth slip
Fault line
The energy radiates _____ from the fault in all directions in the form of seismic waves like ripples on a pond
Outward
The study of earthquakes and the waves they create
Seismology
A scientist who studies and measures earthquakes
to learn more about them and to use them for geological
discover
Seismologist
Recordings of the ground shaking at the specific location of the seismograph
Seismograms
Recording instruments used to record the motion of the ground during an earthquake
Seismographs
The internal part of the seismograph, which may be a pendulum or a mass mounted on a spring; however, it is often used synonymously with seismograph
Seismometer
The place of origin of the earthquake in the interior of the earth
Focus/Origin/Center/Hypocenter
The place on the earth’s surface, which lies directly above the center of the earthquake
Epicenter
The point on the earth’s surface diametrically opposite to the epicenter
Anticenter
The imaginary line that joins the center and the epicenter. This represents the minimum distance which the earthquake has to travel to reach the surface of the earth
Seismic Vertical
An imaginary line joining the points of the same intensity of the earthquake
Isoseismal
An imaginary line which joins the points at which the earthquake waves have arrived at the earth’s surface at the same time
Coseismal
The form of the transmitted energy released from the focus at the time of the earthquake
Seismic Waves
Proportional to the energy released by an earthquake at the focus. It is calculated from earthquakes recorded by a seismograph.
Magnitude
The strength of an earthquake is perceived and felt by people in a certain locality.
Intensity
Earthquakes with a focus depth of less than 50 km
Shallow Earthquakes
Classification of Earthquakes
- Based on depth of focus
- Based on the cause of occurrence
Earthquakes with a focus depth of more than 50 km but less than 250 km
Intermediate Earthquakes
Earthquakes with a focus depth of more than 250 km
Deep Earthquakes
Exclusively due to internal causes, i.e., due to disturbances or adjustments of geological formations taking place in the earth’s interior
Tectonic Earthquakes
Earthquakes that are generally due to external or surficial causes
Non-tectonic Earthquakes
The outer crust of the Earth is divided into rigid plates that are
called ___________.
Tectonic Plates
The edges of tectonic plates
Plate Boundaries
Types of fault
Normal Fault
Reverse Fault
Strike Slip Fault
The primary body wave; the first seismic wave detected by seismographs; able to move through both liquid and solid rock.
P-Waves
Secondary body waves oscillate on the ground perpendicular to the direction of wave travel. They travel about 1.7 times slower than P waves. Because liquids will not sustain shear stresses, This wave will not travel through liquids like water, molten rock, or the Earth’s outer core. This wave produces vertical and horizontal motion on the ground surface.
S-Wave
Surface waves that move in an elliptical motion, producing both a vertical and horizontal component of motion in the the direction of wave propagation.
Rayleigh Wave
Surface waves that move parallel to the Earth’s surface and perpendicular to the direction of wave propagation.
Love Wave
Provides information on significant earthquakes and tsunami events that may significantly impact our country
Philippine Institute of Volcanology and Seismology (PHIVOLCS) National Earthquake Monitoring and Information Initiative
Gives us the earthquake provisions to design seismic-resistant structures to safeguard against major structural damage that may lead to loss of life and property
National Structural Code of the Philippines (NSCP) 2015 in Section 208: Earthquake Loads
The procedures and the limitations for the design of structures shall be determined considering these factors.
Seismic zoning, site characteristics, occupancy, configuration, structural system, and height under the code.
