Geologic Time Scale and Dating Techniques

Study Notes

The geologic time scale is a timeline of Earth's history based on the rock record.
It's divided into four eons: Hadean, Archean, Proterozoic, and Phanerozoic.
Hadean (4570 to 4850 Ma): The earliest eon, representing the period before the Earth's formation, to about 3.85 billion years ago.
Archean (3850 to 2500 Ma): The period immediately following the formation of Earth, showing the early stages of geological activity and life's emergence.
Proterozoic (2500 to 540 Ma): The period showcasing the evolution of life forms, showing major geological events and significant transformations.
Phanerozoic (540 Ma to present): The most recent eon, characterized by the diversification of many life forms.

Relative dating techniques establish the order of events without providing precise ages.
Absolute dating techniques determine the numerical age of geological features.
They are based on the radioactive decay of isotopes in minerals.
Potassium-Argon and Uranium-Lead dating methods are widely used to determine the numerical ages of rocks.
Key scientists include William Smith, who made a large-scale geologic map of Great Britain.
Key concepts of relative dating include superposition and the ordering of rock layers.
Key methods of relative dating include the principle of superposition, inclusions, cross-cutting relationships, unconformity, faunal succession, and horizontality.

Hydrometeorological hazards are atmospheric, hydrological, or oceanographic processes that cause harm to property and life.
Examples include tropical cyclones, typhoons, hurricanes, thunderstorms, hailstorms, tornadoes, cold spells, heavy snowfall, floods, flash floods, droughts, heat waves, storm surges, avalanches, and blizzards.
These events can lead to significant damage and loss of life.

Satellites are advanced tools for tracking and visualizing the formation and path of cyclones.
Doppler radar measures the direction and speed of moving weather phenomena, helping with forecasting and identifying regions of severe weather.

Establishing coordination with local disaster agencies is crucial for preparedness (BDCC and personnel).
Understanding expected hazard impacts and strengthening structures to withstand weather are important preventative measures.
In times of natural disasters, people are encouraged to monitor weather reports, evacuate to safer areas if necessary, and take appropriate safety measures.

It's a project from the department of science and technology(DOST) for forecasting, monitoring, assessment, and information services regarding natural hazards.
It aims to create a more accurate, integrated, and responsive disaster prevention and mitigation system in high-risk areas in the Philippines.
Components include distributing hydrometeorological devices, assessing disaster risk, enhancing georisk mapping, assessing coastal hazards and storm surge risk, developing a flood information network and enhancing development of Doppler radar systems.

Coastal processes, such as waves, tides, sea level changes, crustal movement, and storm surges, shape coastlines and create hazards.
Coastal erosion involves the wearing away of land due to destructive waves.
Submersion is the act of a coastal area being completely held under the water, either gradually or suddenly.
Saltwater Intrusion is the movement of saltwater into groundwater sources.

Mitigation methods include maintaining vegetation, monitoring, adjusting laws, artificial recharge, engineering structures, beach nourishment, and the prevention of mining activities.