Hello, my name's Mr. March.

I'm here today to teach you all about the impacts of volcanoes in a developed country and an emerging country.

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

So by the end of today's lesson, you will be able to use located examples to assess the impacts of volcanic eruptions in a developed and an emerging country.

There are two key terms for today's lesson.

Those are primary impact and secondary impact.

Primary impact refers to the immediate impacts of a tectonic hazard, which are directly caused by it.

Secondary impact refers to indirect effects that occur as a consequence of a tectonic hazard's primary impacts.

There are two learning cycles for today's lesson.

We're gonna start with learning cycle one, which is impacts in a developed country.

Now, Eyjafjallajokull is a stratovolcano in Iceland, and it erupted between March and May, 2010.

It is actually located near the south coast of Iceland, as you can see on the map in front of you.

And it's located on a divergent plate boundary where the two plates are pulling apart.

We can see on the map in front of you that is the North American plate pulling to the west and the Eurasian plate pulling to the east.

So those are the two different tectonic plates which are being involved in this plate movement.

So Lucas says something really interesting.

He says, "I thought volcanoes on divergent plate boundaries were shield volcanoes, not stratovolcanoes." Well, Lucas is absolutely correct.

It's a really good point that Lucas makes.

This volcano is unusual.

Iceland does indeed sit on a divergent plate boundary, but it also sits on a hotspot and that is thought to actually create more silica-rich magma, and that stickier magma produces those stratovolcanoes.

Iceland is, without a doubt, a developed country.

It is a rich country, a wealthy country.

It is a developed country.

It is also very sparsely populated, meaning very few people live there relative to its size.

For example, the total Icelandic population is just 390,000 people, and of those 390,000 people, 138,000 people live in the capital city of Reykjavik.

We have our learning check then and it says to connect the details for that 2010 eruption.

So you can see the information type on the left-hand side, and then you have the facts on the right-hand side.

What you need to do then is pause the video here whilst you connect those two details together.

Well, the date of eruption then matches with the March to May, 2010, so it spread out over many, many months.

The country affected was, of course, Iceland.

The type of plate boundary was divergent.

The volcano type was a stratovolcano, and the tectonic plates involved were the North America and the Eurasian plates.

So really, really well done if you're able to connect any of those details in front of you.

So what are primary and secondary impacts of a tectonic hazard? Well, first of all, primary impacts are immediate and caused directly by the tectonic hazard itself.

The buildings were destroyed by lava flow.

So a lava flow is a primary impact that has caused buildings to be destroyed.

While secondary impacts are indirect impacts and occur in the hours, days, weeks, even months after the hazard.

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

So the primary impact is that the building was destroyed and the knock-on effect of that is that those people were made homeless, and this, therefore, is the secondary impact.

What were the primary impacts of the 2010 Icelandic eruptions? Let's have a look at those now.

So we can see we have lava flows and we have ash fall.

What were the direct impacts on people then? Well, with regards to lava flows, there were really no direct impacts on people.

In terms of direct impacts on property, though, well, around one kilometre squared of land was covered by lava flows, but farmland and buildings were not really affected.

What about ash fall? Well, locally, 500 people were evacuated from the area around the volcano, and a massive ash cloud spread over Europe, which affected air quality.

In terms of direct impacts on property from ash fall, well, fields were coated with ash so that livestock couldn't actually reach the grass to feed.

Water sources were contaminated with ash, affecting livestock, as well as damage to aeroplane engines from volcanic glass particles in the ash cloud.

So what were the knock-on or secondary impacts of the 2010 Icelandic eruptions? Let's start with jokulhlaup flooding.

What were the indirect impacts on people? Well, 800 people were evacuated from the Markarfljot River area.

In terms of indirect impacts on property, there wasn't a real impact.

Bridges and roads were undamaged.

What about the economic impacts? What were their indirect impacts on people? Well, 107,000 flights were cancelled due to the ash cloud, which affected 10 million passengers.

50,000 Kenyan farmers lost export earnings to Europe simply because they couldn't ship or transport their agricultural produce to Europe because of the ash fall in the atmosphere.

And finally, economic cost to Icelanders was around US$200 million.

And what about the indirect impacts on property then? What were the economic impacts there? Well, airlines lost an estimated 130 million pounds each day for the six and a half days that flights were cancelled.

There was no real lasting impact to the Kenyan farmers in terms of property.

And finally, the total economic cost of disruptions to air travel and trade ended up at around US$4.

7 billion.

So time now for a learning check and it says, who do you think is right? And you can see you've got four statements on the screen in front of you, one from Aisha, one from Jun, one from Sofia, and one from Alex.

What you need to do then is pause the video here whilst you read through those four statements and you select all answers that you think are correct.

And the correct answers were from Aisha and from Alex.

Aisha says that the 2010 Icelandic eruption primary impacts were quite limited.

That's due to Iceland's sparse population, right? And Alex says, well, the secondary impacts were huge.

10 million passengers were affected.

Really, really well done if you're able to identify those two as the correct answers.

Time now for another learning check and it says, true or false? An ash cloud is a primary impact of a volcanic eruption, but economic losses due to planes being unable to fly because of ash particles is a secondary impact.

So what you need to do then is pause the video here whilst you read back through that statement and then carefully consider and select your answer.

And the correct answer is true.

Now what you need to do once again is pause the video whilst you consider as to why this statement then is true.

And the reason it's true is because, well, secondary impacts are an indirect result of a volcanic eruption.

The volcano erupting through an ice cap creates glass-like particles that can damage aeroplane engines, which means planes do not fly in areas covered by the ash cloud, which then causes that knock on economic loss.

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

Our next learning check says to complete the missing numbers.

Now you can see you've got five different impacts, primary and secondary there mentioned.

What you need to do then is pause the video here whilst you read through those statements, and do your best to recall the information or the statistical number that matches that statement.

Best of luck.

And the answers were: So the number of people evacuated due to ash fall was 500.

The number of deaths caused by primary impact was zero.

The number of people evacuated due to jokulhlaup is 800.

The number of flights cancelled due to ash cloud was 107,000, and the cost per day of flight cancellations due to the ash cloud was at 130 million pounds.

Really, really well done if you're able to recall any of those numbers that you see in front of you.

We're now to our one and only practise task for the first learning cycle.

And it says, using the map that you can see on the left-hand side and your own knowledge, describe the primary impacts and secondary impacts of the 2010 Icelandic eruptions.

Make sure you say which developed country you are actually writing about.

Now, if you study the map on the left, you can see that these are airports affected by the ash cloud created by those volcanic eruptions.

So what I'd like you to do then is pause the video here whilst you attempt this practise task.

Best of luck.

In terms of feedback then, your answer using your own knowledge could have included the following: The 2010 eruptions then took place in the developed country of Iceland.

Primary impacts included lava flows and ash falls.

And around one kilometre squared of land was actually covered by lava flows, but farmland or buildings were not affected.

No people were killed by the eruptions, but 500 people were evacuated from the area around the volcano because of ash fall, which covered fields and contaminated water sources.

Secondary impacts included jokulhlaup flooding, which caused 800 people to need to be evacuated and an ash cloud across Europe, which meant that 107,000 flights were cancelled at a cost of 130 million pounds per day.

The map shows information about two of the impacts from the eruptions.

It shows the area covered by a layer of ash at least one centimetre thick, which affected a small area in the south of the Iceland.

This confirms that the primary impacts in Iceland were not that extensive.

In contrast, the map shows that the area affected by the secondary impacts was actually very large.

The ash cloud caused flights to be cancelled, which affected airports in northern Europe, western Europe, central Europe, and eastern Europe.

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

We're now to our second and final learning cycle, and this is all about the impacts in an emerging country.

We're gonna look at Mount Merapi, which is a stratovolcano located in Java, Indonesia, and it erupted in October to November, 2010.

We have a wonderful visualisation of Mount Merapi in front of you, and actually we can use GIS, or Geographic Information Systems, to actually explore Mount Merapi and its location.

Indonesia then is near the convergent boundary between the Australian plate and the Eurasian plate.

Now remember, a convergent boundary are where two plates are colliding with each other.

Mount Merapi is Indonesia's most active volcano with many previous eruptions, and we can see those detailed on the map in front of you.

We can see the route of previous pyroclastic flows from Mount Merapi.

Java has one of the highest population densities in the world, with 600 people per kilometre squared.

So it puts a lot of people at risk from an eruption from Mount Merapi.

Around 70,000 people live in the region around Mount Merapi, and Yogyakarta City has a population of 3 million people, and it's only 25 kilometres from the volcano itself.

So a quick learning check, it says to connect the details from the Mount Merapi eruption with the fact.

So what you need to do then is pause the video here whilst you do your best to match those two together.

Best of luck.

And the answers were: So date of eruption was between October and November, 2010.

The country affected was Indonesia.

The type of plate boundary is convergent.

The volcano type is, again, a stratovolcano, and the tectonic plates involved were the Australian and the Eurasian.

So really, really well done if you're able to identify any of those correct answers in front of you.

What were the primary impacts then of the 2010 Mount Merapi eruptions? Let's start with those pyroclastic flows.

What were the direct impacts on people? Well, unfortunately, 353 people were killed and 570 people injured and over 350,000 people needed to be evacuated.

What were the direct impacts on property caused by pyroclastic flows? Well, it spread, those pyroclastic flows spread up to three kilometres from Mount Merapi, which destroyed absolutely everything in its way.

In terms of ash fall, then, how did it directly impact people? Well, it impacted people locally.

Thousands were affected by respiratory problems, irritated eyes and skin problems. In terms of those impacts on property then, well, the ash spread 480 kilometres from Mount Merapi, which caused roofs to collapse on some buildings, smothering crops, clogging rivers, and causing livestock deaths.

And ash cloud also spread across the region, which again affected air quality and undoubtedly would've affected people.

In terms of further impacts to property, well, damage to aeroplane engines from volcanic glass particles in the ash cloud was again, much like the Icelandic eruptions, was again another direct impact on property.

In terms of the secondary impacts then, those knock-on impacts of the 2010 Mount Merapi eruptions, what did those look like? Well, secondary impacts, one real key secondary impact are lahars, and four people were actually killed by those volcanic mud flows.

In terms of the impacts of lahar on property, those indirect impacts, many homes were buried, especially along the Code River, once again near the City of Yogyakarta.

In terms of displacement, then, another impact or another secondary impact, around 280,000 people were temporarily displaced and weren't able to return home.

In terms of indirect impacts caused by that displacement of people on property, at least 2,500 people had to be resettled because their old homes were now in high hazard risk areas.

What were the economic impacts on people indirectly? Well, 25,000 passengers had their flights cancelled, and farmers lost earnings from crops which were buried by ash and mud.

And once again, what were the economic impacts and those indirect impacts on property? 270 flights were cancelled at Yogyakarta airport and others in central Java, and there were a total economic loss of up to US$600 million.

And half of that came from farming losses.

Time now for a learning check.

And it says to take the correct answers to the following Merapi 2010 eruption facts.

So you can see most dangerous impact, deaths, number evacuated, population density of the region, the number of flights cancelled, and finally, the total economic cost.

You can see that you have 50/50 options.

You have two options for each fact.

So what you need to do then is pause the video here whilst you try to recall the correct facts for each of those different features.

Best of luck.

And the correct answers were pyroclastic flow was the most dangerous impact caused by this eruption.

The number of deaths was up at 353.

The number evacuated was 350,000.

The population density of this region is very high, up at 600 people per kilometre squared.

The number of flights cancelled was 270.

The total economic cost was US$600 million.

Really, really well done if you are able to identify any of those correct answers in front of you.

So how should we compare the impacts of the two eruptions, between Mount Merapi and the Icelandic eruption both happening in 2010? Well, Alex says that, "Nothing is more important than people's lives, so the number of deaths should be what we compare." Jun says that, "The total cost of a disaster in US dollars is the best indicator: it shows how much damage was actually caused." Izzy says that, "The number evacuated is best because that tells us about the scale of the impacts on the local people." And finally, Lucas says that, "The different volcanoes have different hazards, so we must compare the volcano and its eruption type." Now what I'd like you to perhaps do is pause the video here whilst you consider as to who you think is correct.

Well, the truth is, there is no one single correct answer.

These statements are all as valid as one another.

What we can do though is that we can combine a number of different indicators when comparing eruptions to try to decide perhaps which one had the most impact.

Time now for another learning check, and it says the 2010 Icelandic eruption's impacts were more significant than Mount Merapi's impacts in 2010.

Which of these support that arguments? What you need to do then is pause the video here whilst you read through those four options and you decide what you think is the correct answer.

And the correct answer is C, total economic cost.

So really, really well done if you are able to identify that as the correct answer.

And our next learning check says, true or false? Impacts of volcanic eruptions are always more severe in developing and emerging countries than in developed countries.

So what you need to do then is pause the video here whilst you read back through that statement and then decide your answer, true or false? And the correct answer is false.

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

And the reason it's false is because economic impacts are often highest in developed countries because of the higher value of the property impacted by the eruption.

In the case of Iceland's 2010 eruption, the eruption had huge economic costs because of the secondary impact of the ash cloud on flights and therefore, on trade.

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

We're now to our two final practise tasks for our final learning cycle.

And it says, complete this table comparing the primary impacts and secondary impacts of Iceland's 2010 eruption and the Mount Merapi eruption in Java, Indonesia in 2010.

The second practise question says, assess the importance of the impacts of two volcanic eruptions that you have studied and some hints to help you with this question.

It says, name the examples you're going to use and the countries that they're in.

Explain what is meant by impacts, refer to primary impacts and secondary impacts.

Explain what you're going to use to judge importance.

For example, is it economic, is it numbers killed, et cetera.

And finally, assess means weigh up.

So consider more than one indicator of importance and then give an overall conclusion.

So what you need to do right now then is pause the video here whilst you attempt these two practise tasks.

Best of luck.

And now some feedback.

So the first question asks you to complete the table, comparing the primary impacts and secondary impacts between the Indonesian and the Icelandic eruptions of 2010.

Let's have a look at those now.

So the number of deaths in Iceland was at zero, in Java it was 353.

The number of people evacuated in Iceland was 1,300 versus in Java, it was 350,000.

The population density of each region was five in Iceland and 600 in Java.

The number of flights cancelled was 107,000 in Iceland, whilst it was only 270 in Java.

Finally, the total economic cost was $4.

7 billion in the Icelandic eruption and $600 million in Java.

Now the second question asked you to assess the importance of the impacts of two volcanic eruptions that you've studied.

And here was just one approach, which you may also have followed.

It says, I'm going to compare the 2010 eruption of Mount Merapi in Java, Indonesia with a 2010 eruption in Iceland, also in 2010.

The Mount Merapi had very severe primary impacts, particularly pyroclastic flows, which killed 353 people.

In contrast, the primary impacts in Iceland's eruption were less severe.

Ash fall led to evacuations, but no one was killed.

For that reason, it could be said that Mount Merapi's impacts were more important because nothing is more important than human lives lost.

The answer continues.

Secondary impacts were significant in both eruptions, with around 2,500 people permanently displaced in Java, for example.

However, because of the indirect effect of flight cancellations across Europe resulting from the ash cloud, the Icelandic eruption ended up costing a colossal $4.

7 billion.

That compares with $600 million as the total economic cost of the Mount Merapi eruptions.

The economic impact of the Icelandic 2010 eruptions was therefore much more significant than that of Mount Merapi, making it more important.

Comparing deaths might not be a very reliable way of assessing importance, because actually very few people live near the volcano, which erupted in Iceland in 2010, and it was just five people per kilometre squared, while the population density around Mount Merapi is high, at 600 people per kilometre squared.

There were far fewer people at risk in Iceland.

Now, the Icelandic eruptions of 2010 were also much less dangerous than Mount Merapi's, which featured pyroclastic flows, one of the most deadly hazards of volcanic eruptions.

Comparing economic impacts might not be a very reliable way of assessing importance.

However, because of the secondary impacts caused by Iceland's 2010 eruption, and because these were so big due to the ash cloud affecting much of Europe, which is a very wealthy region with a lot of air travel.

Indonesia is an emerging country, and so one reason why the economic impacts of the Merapi eruption are lower might be because property in Indonesia, and other things like regional air travel, are not as expensive.

The same impact would cost more in Europe than in Indonesia, therefore, not a reliable comparison.

There are also problems with using both primary impacts, for example, deaths, and secondary impacts, for example, economic costs, to decide which eruption is more important.

In my view, the number of people evacuated is a better measure of importance because that tells us about the scale of the impacts on local people.

Now, 350,000 people were evacuated from around Merapi in 2010 compared to 1,300 people from the volcano which erupted in Iceland in 2010.

And for that reason, I would assess the Merapi 2010 eruption as being more important than the Icelandic 2010 eruption.

So we're now to our learning summary and what we need to know from today's lesson.

Well, in 2010, stratovolcanic eruptions occurred in both Indonesia and in Iceland.

Primary impacts were much more severe in Indonesia, primarily due to the pyroclastic flows in the Mount Merapi eruption.

In the Icelandic eruption, it produced an ash cloud, which covered much of Europe, which had the secondary impact of very significant economic costs.

Different indicators can be considered to assess the significance of primary and secondary impacts.

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.