Hello, my name's Mr. March and I'm here today to teach you all about primary and secondary effects and responses to tectonic hazards.

So, grab everything that you need for today's lesson and let's get going.

So, by the end of today's lesson, you'll be able to explain the difference between primary and secondary effects of a tectonic hazard and between immediate and long-term responses to a tectonic hazard.

There are four key terms for today's lesson, and those are primary effect, secondary effect, immediate response, and long-term response.

Primary effect refers to impacts that occur instantly and as a direct result of the earthquake or volcanic eruption.

Secondary effect refers to the impacts that follow as a consequence of the earthquake or volcanic eruption in the hours, days, and weeks that follow.

Immediate response refers to action taken during and immediately after a hazard event that focuses on surviving the hazard and providing short-term relief.

Long-term response refers to action that focuses on rebuilding after the tectonic hazard and reducing risks from future hazards.

There are three key learning cycles for today and we're gonna start with the first, which is primary and secondary effects of earthquakes.

Now, this photo in front of you is showing the damage caused by an earthquake, and I have two questions for you now, which is, "How did an earthquake cause this level of damage?" And second of all, "What problems do the people who lived in the damaged houses now face?" Now, you may like to pause the video here whilst you've consider your own answers to those two questions, or if you are near someone, you may like to discuss those two questions.

So, in terms of our responses to this then, well, how did an earthquake matter to cause this damage? Alex says, "When the ground shook, the buildings collapsed," and that is absolutely correct.

The shaking motion of the earth during an earthquake sometimes can be just 10 seconds, but that can be enough to bring structures, such as buildings and other infrastructure down.

It can cause it to collapse.

In terms of what problems do the people who lived in these damaged houses face, well, again, Alex is absolutely correct.

He says that people may have died being trapped inside those buildings and underneath all that rubble.

They may have been injured.

But also, survivors will be homeless.

And actually, there are many, many other impacts, which we'll discuss later in the lesson.

Primary effects, then, of an earthquake are caused by the earthquake itself.

They happen in the immediate aftermath of the earthquake itself.

They are also called primary impacts.

So, earth shakes, house falls, this is a primary effect or primary impact of an earthquake.

The buildings collapse when the ground shook.

This is a primary impact, just as Alex says in front of you.

So, ground shaking leads to buildings collapsing, and this is a primary effect, as Aisha once again correctly says.

Now, secondary effects of an earthquake are indirect results of the earthquake.

They are often called secondary impacts.

They are basically a knock on effect of that primary impact that we looked at on the previous slide.

So, Alex is again absolutely correct when he says that a secondary impact would be that survivors became homeless as a result of the earthquake damage.

It was a knock on effect of that earthquake which destroyed people's houses.

The knock on effect is that they are now homeless.

And once again, Aisha is absolutely correct.

Homelessness is a secondary effect or secondary impact.

The earthquake destroyed the homes, which led to homelessness time.

Time now for a learning check and it says, "Which of these are primary effects of earthquakes?" Now, you've got four options in front of you.

What I'd like you to do is pause the video whilst you read through those four options and then consider and select all answers that apply.

Best of luck.

And the correct answers were b and d.

So, fractured gas pipelines due to ground movement, and d, deaths due to falling debris.

So, really, really well done if you are able to identify those two primary effects.

And another learning check says, "Which of these are secondary effects of earthquakes?" Now, once again, you have four options in front of you.

What I'd like you to do is pause the video whilst you read through those and then consider and select all the answers that you think apply.

Now, the correct answers were a, c, and d.

So, remember, secondary effects happen as a indirect result of the earthquake, basically something the earthquake causes which then has a secondary impact.

So, for example, homelessness happens as a result of the earthquake destroying homes.

Fires happen as a result of the earthquake fracturing or breaking gas pipes.

The gas leaks out and something, a spark of some kind ignites it and fires spread.

Diseases spread because the earthquake destroys sanitation, people can't dispose of their waste safely.

Roads may be blocked, so clean water can't be brought in.

And so, when people are living on the streets or in camps, diseases spread quickly in these conditions, conditions created as a result of an earthquake.

So, some effects of earthquakes are really not easy to categorise.

Tsunamis occur as a result of earthquakes moving the seabed, which displaces the water above, creating powerful waves that travel across the ocean.

Now, does that mean it's a primary or a secondary effect of an earthquake? Well, we have two different answers, one from Andeep.

And Andeep says that tsunamis cause flooding and drowning and they destroy buildings, which are primary effects.

Sam says, "Tsunamis happen as a result of an earthquake moving the seabed, so the are secondary effects of earthquakes." Now, you may like to pause the video here whilst you once again read through those two answers from Sam and Andeep and you can consider whether you think that a tsunami is either a primary effect or a secondary effect.

You may like to pause the video here at this point.

But the correct answer is Sam.

Yes, tsunamis happen as a result of the earthquake moving that seabed upwards, so they are a secondary effect of an earthquake.

Now, another effect which is really, really difficult to categorise as an effect of an earthquake are landslides.

Now, landslides occur as a result of earthquakes shaking the ground, which destabilises slopes after which soil and rock slides downhill.

Now, once again, is this a primary or secondary effect of an earthquake? Again, Andeep says that it's a secondary effect because the landslide happens after the earthquake has destabilised the ground, while Sam says it's a primary effect because it is like debris falling off buildings as a result of earthquakes shaking the ground.

You may like to pause the video here whilst you consider your own answer as to who is correct in this scenario.

Well, the answer in this case is Andeep.

Andeep is absolutely correct.

But to be honest, this one is really tricky for geographers to categorise, because some would agree with Sam, while others would agree with Andeep.

Often, landslides happen sometime after the earthquake, which makes them easier to categorise as secondary impacts, and sometimes as a result of other factors too, such as heavy rainfall, which also makes it easier to see them as occurring as an indirect result of the earthquake.

So, here we can see that Andeep is certainly correct in classifying a landslide as a secondary effect, but certainly a time is a really good indication as to whether an effect is primary or secondary, because primary effects are more immediate.

The buildings collapsed as soon as the ground shook.

Secondary effects occur in the hours, days, and weeks after the hazard.

For example, survivors were homeless for many, many months after the earthquake.

So, perhaps using time is a really good indication as to whether an effect is primary or secondary.

So, a learning check.

True or false? Ground shaking is a secondary effect of an earthquake.

Could you please pause the video here whilst you consider and then select your answer? And the correct answer is false.

Now, what I'd like you to do once again is pause the video whilst you consider as to why this statement is false.

And the reason it's false is because secondary effects of earthquakes are indirect results of an earthquake.

Ground shaking is something that an earthquake directly does, and therefore makes it a primary effect.

Once again, really well done if you were able to get that answer correct.

So, we're on now to our one and only practise question for the first learning cycle, and it says to colour code the following into primary effects and secondary effects.

These are all impacts of the Haiti earthquake from 2010.

So, pause the video here whilst you attempt this practise question.

Best of luck.

So, in terms of feedback then, we can see the two colours which denote the different effects, primary in green and secondary in blue.

Let's start with the primary effects.

So, the primary effects were that roads were damaged and blocked by the rubble.

An estimated 220,000 people were killed by collapsed buildings.

About 300,000 homes were damaged or destroyed.

In terms of the secondary effects, the effects which happen after or as a result of the primary effect, this is what I had.

So, but by July, 2011, cholera had killed almost 6,000 people.

600,000 people left Port-au-Prince to stay with friends and relatives, increasing social pressure elsewhere in Haiti.

Thousands of landslides in the hills surrounding Port-au-Prince destroyed many properties.

And finally, severe destruction of the harbour delayed emergency supplies entering the country by sea.

So, really, really well done if you too were able to get the answers that you can see on the screen in front of you.

We're on now to our second learning cycle, and it says the primary and secondary effects of volcanoes.

So, what do you think some primary effects of volcanic eruptions might be? You may like to pause the video here whilst you consider your own answer to that question, or perhaps even discuss it with someone near you.

So, what are the primary effects of volcanic eruptions? Well, the first of which is the most identifiable, those lava flows, which destroys anything in its path.

Yes, they can sometimes be redirected or channelled away from properties and settlements, but generally, this is the case.

They are unstoppable.

Yes, they move very slowly, but they are unstoppable and will cause damage and destruction to anything in its path.

Then there are the pyroclastic flows, the most deadly of the effects of volcanic eruptions, which will destroy, kill, or burn anything in its path.

Then there is ashfall.

Now, ash falling from the sky falls onto houses' roofs, and over time this extra weight can cause roofs to collapse.

It can also contaminate water sources and also cover farmland, thereby lead into a decrease in crop production as well.

And finally, poisonous gases, which can be responsible for killing humans, livestock, and wild animals.

So, what might be some of the secondary effects of volcanic eruptions? Here are three relating to just ashfall.

Now we have those three images.

Let's start by having a look at the image on the left.

It says that ash in the atmosphere can block incoming solar radiation, which can actually cause climate cooling.

Crop failures, which you can see in the right hand image, can result from ash covering farmland and damaging crops.

And finally, ash in the atmosphere can damage plane engines, leading to massive air travel disruption.

So, a quick learning check, and it's based on those four primary effects which I talked you through just a moment ago.

It says to complete the missing primary effects of volcanic eruptions.

So, what I'd like you to do is pause the video here whilst you try to recall that information and then think of the correct answer.

Best of luck.

Now, the correct answers were lava flows, pyroclastic flows, ashfalls, and poisonous gases.

So really, really well done if you are able to recall those four different effects of volcanic eruptions.

And our second learning check says which of the following would be secondary effects of a volcanic eruption? So, once again, I'd like you to pause the video here whilst you read through those four options and then consider and select all answers that you think apply.

And the correct answers were a and b, a, crop failures after ashfalls covering farmland, and b, disruption in air travel due to ash clouds.

Really, really well done if you were able to identify those two correct answers.

We're on now to our one and only practise question for learning cycle two, and it says to read this information in front of you about a volcanic eruption and list the primary effects and secondary effects.

So, pause the video here whilst you attend this practise question.

Best of luck.

And now some feedback.

And in terms of the primary effects, this is what you may have answered.

So, lava flows and ash covered farmland, harming crops and livestock.

Second, the eruption released toxic gases affecting air quality.

And finally, the eruption produced a massive ash cloud that spread over Europe.

In terms of the secondary effects, this is what you may have answered.

Melting ice caused floods that damaged roads and forced evacuations.

The massive ash cloud grounded flights for weeks, this disrupted businesses and imports were delayed in many European countries.

Tourism and farming in Iceland suffered for a while because of the travel disruption for tourism and the ashfall for farming.

But in the long term, the ash actually improved soil fertility, which helped farming.

And tourism was boosted because people wanted to come to Iceland to see the volcanoes.

So, really well done a you too had those answers in front of you.

We're on now to our third and final learning cycle, which is all about the immediate and long-term responses.

Now, an immediate response to a tectonic hazard focuses on surviving the hazard itself and providing short-term relief.

Long-term responses focuses on rebuilding after the tectonic hazard and reducing the risks from future tectonic hazards.

So, examples of immediate responses could include any of the following.

So, let's start with those short-term relief options.

There are the rescue operations to try and save people perhaps trapped in rubble after an earthquake.

There's that emergency medical care that really needs to try and save the victims of a tectonic event.

There's the emergency warnings and alerts perhaps for future tectonic events, or for that tectonic event itself.

There's the evacuation of people to get people away from areas which are at risk.

Then there's the distribution of clean water, food, and shelter.

So, a quick learning check.

True or false? Actions taken over the weeks, months, and years following a tectonic hazard are known as immediate responses or short-term relief.

So, pause the video here whilst you consider and then select your answer.

And the answer was false.

Now, once again, I'd like you to pause the video whilst you consider as to why this statement is false.

And the reason it's false is because actions taken over the longer term are known as long-term responses.

Immediate responses to tectonic hazards focus on surviving the hazard itself and providing short-term relief.

So, really, really well done if you were able to identify those two correct answers.

Again, examples of a long-term response could include the following.

So, it's all about rebuilding and repairing the damage or destruction caused by a tectonic hazard, such as an earthquake.

Then, the country or the area is going to need vast amounts of economic support, bringing investment into that area to get people back on their feet, to rebuild their homes, to rebuild their lives, to rebuild businesses and employment.

Then there's also improving warning and monitoring systems to ensure that next time a tectonic event happens like this, that people have more warning about those events, that they're able to track and monitor perhaps the seismic waves or those sort of earthquakes which can lead up sometimes to the main earthquake to try and give people more warning to perhaps evacuate from that area.

Then there's educating people about what to do during the hazard.

So, perhaps during an earthquake, school children can be drilled on what to do during an earthquake, whether it's getting under a table or perhaps getting outside.

Whatever it is, people can be educated to try and reduce the number of fatalities and injuries caused by a tectonic event.

And then finally, there's the helping the environment to recover.

This is particularly true with a volcanic eruption, which can decimate the environment.

Well, a long-term response to that is certainly trying to bring some investment into helping the environment recover from a devastating volcanic eruption.

So, if we focus on rebuilding and repairing, well, long-term rebuilding and repairing for earthquake hazards, for example, can include constructing earthquake-proof buildings.

These reduce the risks from future earthquakes.

Next, we have economic support, so government providing money to help businesses and farmers affected by the hazard itself to get them back on their feet in the weeks, months, and years after that hazard event.

Improving warning systems, so being able to reduce future hazard risk is vitally important by upgrading perhaps earthquake and tsunami and volcano monitoring and warning systems. In fact, this was something that was massively invested in in Southeast Asia after the 2004 Boxing Day tsunami to ensure that people were given much, much more warning should something like it ever happen again.

And next we have educating people about hazard risk, for example, regular earthquake and tsunami drills in schools or workplaces, clearly defining evacuation routes which are clearly signposted so people know exactly where they need to go should a tectonic event ever occur.

And finally, helping the environment to recover, for example, replanting slopes that have lost trees after a landslide can really help restore its stability and thereby reduce erosion, and actually prevent perhaps further landslides in the future.

So, a quick learning check.

It says who understands best why building earthquake-proof buildings is a long-term response rather than an immediate response? So, you have Laura and Lucas to read through.

What I'd like you to do is pause the video whilst you read through their statements and then select who you think understands best.

So, pause the video here whilst you attempt this learn check.

And the correct answer was Lucas.

Now, Lucas says that, "As well as taking a long time to build, earthquake-proof buildings are about reducing hazard risk in the future." So really, really well done if you too selected Lucas.

Another learning chick says to match these pictures to the type of long-term responses that they represent.

Only three of the options are correct.

So, once again, pause the video here whilst you look at the images on the left and the long-term responses on the right and match them together.

Remember, only three of the options are actually correct.

And the correct answers were rebuilding and repairing matches to the image on the top, educating people about hazard risks, so doing drills perhaps within schools or workplaces.

And finally, improving warning and monitoring system matches with the bottom image right there.

So, really, really well done if you too selected those three correct answers.

So, we're on now to our two practise questions for the final learning cycle.

And the first one says to add text to complete this diagram of long-term responses.

So, you can see you've got some images there to sort of guide you in what you could write.

And the second practise question says, this photo shows impacts from an earthquake, and there are two different questions within it.

The first one says, "Suggest two likely immediate responses to this event." And the second was to explain two ways in which long-term responses could reduce hazard risk in this area in the future.

So, pause the video here whilst you attempt these two practise questions.

Best of luck.

So, in terms of feedback for the first question, this is what you may have included.

So, in the top left image, we needed to mention that rebuilding and repairing are a fantastic long-term response.

There's also economic support, improving warning and monitoring systems so that people are, yeah, better warned and they can perhaps evacuate from the area which is at risk.

Then there's educating people about hazard risk, perhaps in businesses or in schools, and finally, helping the environment to recover.

And for the feedback for the first part of the second question, you were asked to suggest two likely immediate responses to the image in front of you.

This is what you may have included.

So, rescue operations to try and save as many people in the immediate aftermath of the earthquake that you can see in front of you.

Emergency medical care, emergency warnings and alerts, evacuating people from areas at risk, and distributing clean water, food, and shelter.

For the second part of that second question, you were asked to explain two ways in which long-term responses could reduce hazard risk in this area in the future.

Your answer could have included rebuilding the houses in this area as earthquake-proof buildings would help to reduce hazard risk because it would mean that buildings would not collapse again in the future like they have done in the photo.

That would reduce the risk of death and injury.

Another long-term response would be to educate people about how to reduce the hazard risk, for example, by having regular drills in schools so children know exactly what to do to protect themselves in the event of an earthquake.

So, really, really well done if you were able to include anything like that in your own answer.

So, in terms of our learning summary, primary effects of an earthquake are caused by the earthquake itself.

They are also called primary impacts.

Secondary effects are indirect results of the earthquake, so almost like a knock-on effect.

They are also called secondary impacts.

Immediate responses focus on surviving the hazard itself and providing short-term relief.

Long-term responses focus on rebuilding after the tectonic hazard and reducing risks from future hazards.

So, really, really well done during today's lesson.

It was a pleasure teaching you and I will see you again on the next lesson.

Goodbye.