HAZARDS CAUSED BY COASTAL PROCESSES / EARTH AND LIFE SCIENCE / SCIENCE 11 - MELC 19

Tantan HD

21 Nov 202008:24

Summary

TLDRThis educational video delves into the impact of coastal processes on shorelines, focusing on erosion, submersion, and saltwater intrusion. It explains how natural forces like waves, tides, and sea level rise, along with human activities, contribute to these changes. The video also discusses the hazards posed by coastal processes, including the five types of coastal erosion and the effects of storms and tectonic movements. It concludes by highlighting the importance of understanding these processes to mitigate their impacts.

Takeaways

🌊 Coastal processes such as weathering, erosion, and sediment shift are the main driving forces behind shoreline changes.
🏖️ Waves, both gentle during summer and powerful during storms, play a significant role in coastal erosion by carrying and redistributing sediments.
🌀 Tides, influenced by the gravitational pull of the sun and moon, cause regular changes in sea level, affecting coastal landscapes.
🌊 Sea level rise, currently at about 2mm per year, exacerbates coastal erosion by increasing the reach of waves and water levels.
🌪️ Storms can lead to coastal flooding and erosion, especially when they coincide with high tides, resulting in storm surges.
🌋 Earth crust movements, including earthquakes and tsunamis, can dramatically impact coastal areas through sudden and violent changes.
🏞️ Coastal erosion is characterized by the wearing away of land by the sea, involving processes like abrasion, hydraulic action, and corrosion.
🌊 Submersion occurs when sediment deposition outpaces the transport capacity of waves or currents, leading to the formation of landforms like sandbars.
💧 Saltwater intrusion happens when sea water infiltrates freshwater aquifers, often due to a drop in groundwater levels or a rise in sea levels.
🌍 The Philippines, with its extensive coastline and numerous islands, is particularly vulnerable to the impacts of coastal processes.

Q & A

What are the main driving forces behind shoreline changes?
-The main driving forces behind shoreline changes are coastal processes such as weathering, erosion, and shift.
How do wind-driven waves contribute to coastal processes?
-Wind-driven waves, or surface waves, are created by the friction between wind and surface water, causing recurrent disturbances that lead to the formation of wave crests.
What happens during the swash and backwash of waves on a beach?
-During the swash, waves surge up the shore face and carry sediment. The backwash, having less energy, slides back towards the water, causing the beach to grow in size.
How do storm waves differ from summer waves in their impact on coastal areas?
-Storm waves carry much more energy than summer waves, which allows them to suspend sediments and redistribute them in the nearshore environment, leading to a steeper and narrower beach profile.
What causes tides and how do they vary?
-Tides are caused by the gravitational attraction of the sun and the moon on the oceans. They vary due to the changing relationship between the sun, earth, and moon, resulting in spring tides and neap tides.
What is the significance of spring tides and neap tides?
-Spring tides are when the sun, earth, and moon are aligned, resulting in the highest high tides and lowest low tides. Neap tides occur during the first quarter and last quarter of the lunar month, resulting in the smallest tidal range.
How has sea level rise affected coastal erosion?
-Sea level rise, currently at about 2 millimeters per year, contributes to an increased rate of coastal erosion by allowing more water to interact with the shoreline.
What is coastal flooding and how does it relate to tides?
-Coastal flooding occurs when storms strike a coast at spring tide, leading to a large storm surge. The combination of storm surge and high tide can cause severe erosion and flooding.
What is crustal movement and how does it impact coastal areas?
-Crustal movement, caused by tectonic shifts, can lead to earthquakes and tsunamis, which can dramatically affect coastal areas by causing erosion, submersion, and other hazards.
What are the five common processes that cause coastal erosion?
-The five common processes that cause coastal erosion are attrition, abrasion, hydraulic action, corrosion, and the action of waves.
How is saltwater intrusion related to coastal processes?
-Saltwater intrusion is the movement of sea water into freshwater aquifers, caused by a decrease in groundwater levels or rises in sea water levels, which can be exacerbated by coastal processes.

Outlines

00:00

🌊 Coastal Processes and Their Impact

This video segment delves into the learning competency of understanding coastal processes and their consequences, specifically coastal erosion, submersion, and saltwater intrusion. The Philippines, with its extensive coastline and numerous islands, serves as a prime example of the effects of these natural processes. The video explains that weathering, erosion, and shifting are the primary drivers of shoreline changes. It details how waves, driven by wind, can cause erosion by the swash and backwash actions, and how the beach profile changes between summer and stormy months. Tides, influenced by the gravitational pull of the sun and moon, also play a significant role in coastal dynamics. The video concludes this section by discussing sea level rise, which has been a continuous process since the last ice age, contributing to coastal erosion.

05:03

🌪 Hazards of Coastal Processes

The second paragraph of the video script shifts focus to the hazards caused by coastal processes, including coastal erosion, submersion, and saltwater intrusion. It explains that coastal erosion is the wearing away of land by the sea, often due to destructive waves. The paragraph outlines five common processes contributing to coastal erosion: attrition, abrasion, hydraulic action, corrosion, and attrition. Submersion is described as the phenomenon where sediment exceeds the transport capacity of waves or currents, leading to the formation of features like sandbars. Saltwater intrusion is the movement of seawater into freshwater aquifers, caused by a decrease in groundwater levels or a rise in sea levels. The video also touches on additional hazards such as coastal flooding, which can be exacerbated by storms during spring tides, and the geological impacts like earthquakes and tsunamis due to crustal movements.

Mindmap

Keywords

💡Coastal Processes

Coastal processes refer to the natural phenomena that shape and change the coastal environment. In the video, these processes include weathering, erosion, and sediment shift, which are the primary drivers of shoreline changes. They are inevitable occurrences driven by nature and can be amplified by human actions, leading to hazards such as coastal erosion, submersion, and saltwater intrusion.

💡Coastal Erosion

Coastal erosion is the wearing away of land by the sea, often caused by destructive waves. It is one of the hazards discussed in the video, resulting from various processes such as abrasion, corrosion, and hydraulic action. The video explains that coastal erosion can lead to significant damage to shorelines, which is a critical concern for coastal communities.

💡Submersion

Submersion occurs when the amount of sediment exceeds the wave or current's ability to transport it, leading to the deposition of materials like sand, pebbles, or cobbles along the shoreline. The video describes submersion as a hazard that can result from coastal processes, particularly during periods of high sedimentation or when natural coastal defenses are compromised.

💡Salt Water Intrusion

Saltwater intrusion is the movement of seawater into freshwater aquifers, which can be caused by natural processes or human activities. The video discusses how a decrease in groundwater levels or rises in sea levels can lead to this phenomenon, impacting freshwater resources and posing a threat to coastal ecosystems and human settlements.

💡Waves

Waves, particularly wind-driven waves, are a significant coastal process highlighted in the video. They are created by the friction between wind and surface water and can lead to both the erosion and deposition of sediments along the shore. The video explains how the energy of waves during different seasons, such as summer and stormy months, affects the beach profile and contributes to coastal erosion.

💡Tides

Tides result from the gravitational attraction of the sun and the moon on the oceans. The video explains how the alignment of the sun, earth, and moon during full and new moon phases leads to spring tides, while the right angle alignment during the first quarter and last quarter leads to neap tides. Tides play a crucial role in coastal processes by influencing water levels and the movement of sediments.

💡Sea Level Rise

Sea level rise is discussed in the video as a long-term phenomenon that has been occurring since the last ice age. It is currently contributing to increased rates of coastal erosion as global average sea levels rise at a rate of about 2 millimeters per year. This rise in sea levels can exacerbate coastal flooding and erosion, particularly during storm events.

💡Coastal Flooding

Coastal flooding is a hazard that can be severe when storms strike a coast at spring tide, as explained in the video. It is caused by the combination of storm surges and high tides, leading to the inundation of coastal areas. This can result in significant damage to property and infrastructure, as well as threats to human life.

💡Tectonic Movements

Tectonic movements, or the deformation of the earth's crust due to geological processes, are mentioned in the video as a factor that can cause earthquakes and tsunamis. These events can have dramatic effects on coastal areas, leading to sudden and severe changes in the coastal landscape and posing significant risks to human populations.

💡Shoreline Changes

Shoreline changes refer to the alterations in the shape and position of the coastline over time. The video discusses how these changes are associated with coastal processes and can be influenced by both natural forces and human activities. Understanding shoreline changes is essential for managing coastal resources and mitigating the impacts of coastal hazards.

Highlights

Coastal processes such as weathering, erosion, and shift are the main driving forces of shoreline changes.

The Philippines, with its extensive shoreline, is particularly susceptible to coastal alterations.

Waves, driven by wind, are a significant coastal process contributing to shoreline changes.

Swash and backwash are critical components of the wave action that affects coastal erosion.

Storm waves carry high energy that can lead to coastal erosion and sediment redistribution.

Tides, influenced by the gravitational pull of the moon and sun, play a role in coastal processes.

Spring tides and neap tides have different impacts on coastal erosion due to their tidal ranges.

Sea level rise, averaging 2 millimeters per year, exacerbates coastal erosion.

Coastal flooding during storms at spring tide can lead to severe erosion.

Crystal movement and tectonic activities can cause earthquakes and tsunamis, affecting coastal areas.

Coastal erosion is the wearing away of land by the sea, involving processes like abrasion and corrosion.

Submersion occurs when sediment exceeds the transport capacity of waves or currents.

Sea water intrusion is the movement of seawater into freshwater aquifers, influenced by groundwater and sea level changes.

Coastal processes result in hazards such as erosion, submersion, and saltwater intrusion.

Human actions can amplify the effects of natural coastal processes on shorelines.

The video concludes by summarizing the key hazards caused by coastal processes.