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

Summary

This 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.