HAZARDS CAUSED BY COASTAL PROCESSES / EARTH AND LIFE SCIENCE / SCIENCE 11 - MELC 19
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
🌊 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.
🌪 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 Erosion
💡Submersion
💡Salt Water Intrusion
💡Waves
💡Tides
💡Sea Level Rise
💡Coastal Flooding
💡Tectonic Movements
💡Shoreline Changes
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.
Transcripts
do
[Music]
in this video we will focus our
discussion on the learning competency
describe how coastal processes result in
coastal erosion
submersion and salt water intrusion
at the end of the lesson you should be
able to one
identify different types of coastal
processes
and number two explain the hazards
brought by coastal processes
that results in coastal erosion
submersion and salt water
intrusion everything on earth
undergoes continuous change and for that
reason
everything is temporary in nature while
a number
of these modifications are not easily
noticeable to the naked eye
others are highly evident and have early
detection
just like our shorelines the philippines
being an archipelago with seven thousand
one hundred islands and eighteen
thousand kilometers shorelines
is indeed facing this such inevitable
change
all these coastal alterations can be
associated to coastal processes such as
weathering
erosion and shift which are the main
driving forces of shoreline changes
coastal processes are inevitable
occurrences driven by nature
and amplified by human action
they cause damage to shorelines through
coastal erosion
submersion and salt water intrusion
waves are coastal processes which are
caused by
wind
wind-driven waves or surface waves are
created by the friction between wind and
surface water
as wind blows across the surface of the
ocean or a lake
the recurrent disturbances creates a
wave crest
during summer weather waves gently surge
up the shore face
the swash carries sediment the swash
slows
runs out of momentum then slides back
down towards the water
[Music]
some of the backwash sinks into the sand
the backwash has a little less energy to
carry sediment down the beach
so the beach gradually grows in size
with the development of a summer burn
the summer beach profile is broader than
with a gentler slope
during the stormy months storm waves
carry much
energy to the beach with extra energy to
suspend sediments
and redistribute them in the near shore
environment
steady strong winds from a storm can
push water up on the protected shore
raising water levels return flow from
this
wind setup helps to carry sediment away
from the shore
the summer berm is eroded away and the
sands are deposited
offshore this beach profile is steeper
and narrower
next we have tides
tides result from the gravitational
attraction of the sun
and the moon on the oceans as the moon
orbits around the earth
every four weeks the relationship of the
sun
earth and moon changes
at the full moon in new moon the sun
earth
and moon are aligned at this times the
gravitational and centrifugal force of
the moon
and sun combine together and result to
spring times
[Music]
the spring tides are the highest high
tides and lowest low tides or the
greatest tidal range
during the course of the lunar month
during the first quarter and last
quarter the sun
earth and moon form a right angle on
this times the gravitational force of
the sun
and moon act at right angles to one
another
that result to neptides the niptides are
the lowest highlights and highest low
tides
or the smallest tidal range
next we have sea level rise sea level
has risen by about 120
meters since the peak of the last ice
age about
19 000 years ago since then
ice caps have shrunk returning water to
the sea
and the seas have warmed and expanded
global average sea level is currently
rising at the rate of about 2
millimeters per year
this low sea level rise helps to
increase the rate of coastal erosion
next we have coastal flooding coastal
flooding and erosion may be severe when
storms strike a coast at spring tide
storms brought by low pressure systems
may give rise to a large
storm surge highest water occurs
through the combination of storm surge
at spring time
[Music]
fifth we have crystal movement or the
deformation of the earth's crust due to
tectonic movements
it can cause earthquakes which affect
humans dramatically
it can cause tsunamis that can destroy
coastal areas
now let's discuss the hazards caused by
coastal processes
this include coastal erosion submersion
and salt water intrusion
coastal erosion refers to the wearing
away of the land by the sea
this often involves destructive waves
wearing away the coast
there are five common processes that
cause coastal erosion
we have decoration
abrasion
hydraulic action
attrition
and corrosion
submersion occurs when the amount of
sediment exceeds
wave or current's ability to transport
like the narrow strips of sand
pebbles or cobbles deposited along a
shoreline
sea water intrusion is the movement of
sea water into fresh water aquifers
due to natural processes or human
activities
sea water intrusion is caused by the
decrease in groundwater levels or by
rises in sea water levels
and that ends our lesson congratulations
thank you for watching
thank you
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