Human Impact on the Environment: Understanding the Environmental Crisis
The Human Impact on the Environment
1. Natural Resources
Natural resources are materials derived from nature that humans use to satisfy their basic needs and desires. These resources are categorized as:
- Non-renewable resources: Exist in fixed amounts on Earth and are generated over long geological periods.
- Renewable resources: Replenish naturally at a rate faster than their consumption.
- Potentially renewable resources: Can be replenished naturally but are susceptible to depletion if overused.
Environmental
Read MoreUnderstanding the Geosphere: Structure, Seismic Waves, and Volcanic Hazards
ITEM 6: GEOSPHERE and Geohazards
Geosphere
The geosphere refers to the solid part of the Earth, encompassing everything beneath the Earth’s crust. It is the focus of study for phenomena related to the Earth’s internal dynamics, including its solid materials, surface features, and the planet as a whole.
Structure of the Geosphere
The geosphere’s structure can be categorized based on both physical and chemical composition:
Chemical Composition
- Core: Composed primarily of iron (Fe) and nickel (Ni).
- Mantle:
Plate Tectonics: A Comprehensive Guide to Earth’s Dynamic Surface
Plate Tectonics
Introduction
The thermal motion of the Earth’s interior causes significant changes on its surface, explained by the theory of plate tectonics. This theory proposes that the lithosphere, the Earth’s rigid outer layer, is divided into several fragments called tectonic plates. These plates move horizontally past one another, driven by convection currents and subduction. Numerous pieces of evidence support this theory, including the age of oceanic crust, heat flux in ocean basins, and
Read MorePaleoclimate Proxies and Earth’s Climate History
L15: Proxies of Paleoclimate I
Learning Objectives:
- Explain at least one way that understanding past climate helps our present understanding.
- Define “paleoproxy.”
- Explain the principles behind the four paleoproxies presented.
a. Why Look to the Past?
Studying past climate helps us understand the patterns of climate change better.
b. What is a Proxy?
A proxy is something that, in theory, closely tracks something else we cannot measure directly. For example, grades are a proxy for learning.
c. Paleoproxies
Paleoproxies
Read MoreUnderstanding Earthquakes and Earth’s Structure
The Soil Structure and Seismic Methods
Earthquakes
Definition: A sudden jolt of the Earth’s interior.
Why does it occur? It is due to failures in the Earth’s crust.
Definition of failure: A fracture of the field accompanied by a shift.
Elements of a Failure
Fault Plane or Fault Surface
The area where the fracture occurs and the displacement occurs.
Types of Failure
- Normal Fault or Direct: The fault plane dips toward the collapsed lip. The sunken lip rests on the up. Normal faults are caused by divergent
Understanding River Modeling and Geological Risks
River Modeling
Morphoclimatic-Wet Systems
Rivers, as typical morphoclimatic-wet systems, are the primary carriers of mineral matter from continents to oceans. They possess significant energy, utilized in erosion, material transport, and channel deepening, resulting in a characteristic “V” shape.
Channel Geometry
While watercourses exhibit varying geometry along their paths, they can be categorized into three groups:
- Straight: The channel’s sinuosity is negligible.
- Branched: A series of divisions form