We hope you had a lovely long weekend and spent time with your family outside in the sunshine.
This week we are very excited to be finding out about the planet we live on.
During Space Week saw us learning about what’s happening in outer space
but now its time to have a look at what our own planet is made up of.
There will of course be some fantastic facts for you to amaze your friends and family with by the end of the week.
Come on a journey around and through our very own Planet Earth!
Planet Earth Week - Holiday Monday
It is the holiday weekend, so we will see you on Tuesday, however, our judges have started reviewing your challenge entries.
Remember: You have until
17:00 Monday 25 May 2020
(extended by popular demand) to send your entries in for our two challenges.
See you on Tuesday with a return to our normal format
with lots of daily activities for our Planet Earth Week!
Today we are going to learn about Earths layers.
Have you heard the term “Journey to the Centre of the Earth” ask your family about it - there have been several films made with this title!
The possibility of travelling to the centre of the earth is just for science fiction films but scientists can give us an excellent idea of what the layers of our planet are made up of and how they behave by looking at earthquakes of all things!
Did you know:
By studying rocks and meteorites (rocks from space) scientists believe the Earth is about 4.5 billion years old!
What is the Earth Made of?
So what is Planet Earth made up of...
It's the thinnest layer of the earth.
It is made up of both oceanic and continental crust.
The oceanic crust (the area under our oceans and seas) is roughly 7 km (5 miles) thick and composed of the dark igneous rock basalt. Basalt is formed underwater when lava reached the earth's surface at a mid-ocean ridge - we heard about this when looking at Tsunamis!
The continental crust averages 35 km (22 miles) thick but will be much deeper - as much as 70 km (40 miles) in some mountainous regions of the world.
The Mantle is the second layer of the Earth and makes up around 84% of our planet!
It is divided into 2 sections - the Upper Mantle and the Lower Mantle
The mantle is much thicker than the crust and is almost 3000km deep and is made up of hot, solid rock.
The Tectonic plates are a combination of the crust and the outer mantle
They actually move but very very slowly only a few inches a year
When they touch each other it is called a fault and can cause an earthquake or a volcano- we will learn more about Tectonic Plates later in the week.
The Earths outer core is very very hot and is made up of iron and nickel
It is so hot that it is actually liquid!
It creates something called a magnetic field which is very important as it creates a protective shield around us to protect the earth from the sun's solar winds!
The inner core is made up of iron and nickel also but it is under immense pressure and although just as hot this means it stays solid!
Now have a go at our activity to make a pop-up card activity with all the layers of the earth detailed!
We also have a game for you to play that will help you to learn
all about the layers that make up Planet Earth!
Just do the first level as you will need to learn about Tectonic plates to do the next section!
Let's take a look at the rock type that makes up the continental crust - this is the land area where we walk every day and where our buildings stand.
It is made up mostly of solid rock like granite and then on top of this is what’s called sedimentary rock - this is actually made up of bits of material that have been pressed together over many years such as dead animals and plants.
We would like you to have a look when out on your daily walk - hopefully we will be out more than once soon - and have a look at some stones and rocks and see if you can identify any.
If you have a garden then ask if you can dig a hole - not where the plants are - and see what you can find
Think about Palaeontologists and archaeologists - they dig in the soil looking for fossils and bones and interesting artefacts that have been buried underground for many hundreds of years.
If you use Minecraft you can download
3D Geological Models
and have a look at how our country is made up.
Do you know how Giants Causeway was formed - do some research and see what you can find out - watch this video which gives a few versions of how it all came about!
Now have a look at some of these rocks and minerals and see how many you know.
That's all for today but tomorrow we have lots of exciting activities for you...
See you tomorrow!
Today we are going to find out some more interesting facts about the plates that make up the Earth's outer layer that are actually moving!
They are very large and move exceptionally slowly as we found out yesterday.
When they move like this it is known as Plate Tectonics!
What happens when they bump together - lets find out...
The outer shell of the Earth - the crust or lithosphere - which we heard about on Tuesday - is broken up into these major sections called tectonic plates.
The idea behind plate tectonics is that Earth used to be one large landmass but over many millions of years it separated and now there are large pieces (plates) on the surface of the Earth. The plates are like the skin of the planet.
You can think of them like a giant jigsaw puzzle that covers the Earth underneath the ground. They constantly move around. Although constantly moving its actually only centimetres each year. You couldn't sit down and watch it happen. Or can you? This movement causes all kinds of things to happen, such as volcanoes, earthquakes, and tsunamis as they bump into one another.
Watch the video to find out more...
Volcanoes are formed when heavier tectonic plates collide with and slide underneath lighter tectonic plates. Think of it like pushing 2 biscuits together – one of them will usually go over the top of the other.
The lighter tectonic plate that goes on the top then begins to melt into magma as it pushes up. This magma will slowly harden and pile on top of itself, forming a volcano.
We will learn more about this below...
How do we know this is true and how can we actually tell if they have moved?
Look closely at this map showing what is called the Mid Atlantic Ridge - an entire line of ridges caused by the plates moving -
you can see the split right down the middle of the ocean floor. This is where magma from the mantle has reached the
seafloor erupting as lava and creating this new layer!
Now look at the edges of Africa and South America - do you think they could fit together?
Read the next section to find out more...
The Continents Changing Over Time... The Story of Pangaea
It is understood that the seven continents, that we have today, were once all connected! Let's learn more...
The theory was originally put forward by German geologist Alfred Wegener in the early 20th Century. Wegener theorized that the world's land was all one large supercontinent 200 million years ago. He named this supercontinent Pangaea, which is Greek for All-earth.
Not many people believed him but then over the years many more scientists researching discovered that Wegener was actually correct.
Similar fossils and rocks were found in both the African Continent and the South American Continent suggesting a shared land where animals could roam from the North Pole to the South Pole.
Look at the outline of these continents - do they look like they used to fit together?
Now watch this video to see how the plates will move in the future...
Earthquakes are a sudden and violent shaking of the ground as a result of movements within the earth's crust or volcanic action.
Earthquakes can cause great destruction.
When an earthquake occurs, it transmits seismic waves in all directions through the earth. These seismic waves can be detected using a special machine called a seismograph.
So what happens when the plates collide - one result can be a volcano. As one plate is pulled beneath the other it allows molten rock to push up to the earths surface.
The molten rock and ash solidify as they cool forming that very obvious shape of a volcano!
If you haven’t already make your own volcano following the instructions on the DIY Science page.
You can also watch a video of some real-life Volcanoes...
10. Oil and Sedimentary Rocks
Today we are very lucky to have a guest post from Rachel Meacock who is an environmental consultant working within the energy industry.
Oil is one of the most useful resources in the world. It is used to provide energy, power industry forward, heat our home and provide fuel for vehicles, which in turn carry people and goods all over the world. It’s vital in the production and manufacturing of many everyday items, such as plastic, laundry detergent, paint, printer ink, building materials, and even medicines! Oil is a very useful product, but where does it come from?
Where do we find oil?
Oil is found within reservoirs, deep underground. These reservoirs are made up of sedimentary rocks. There are two types of sedimentary rocks – Clastic and Biochemical.
Clastic rocks are formed following movement, building up and settling of solid particles, like sand and pebbles created from the weathering of larger rocks. These particles are carried to a point of deposit, for example via the movement of a river, and the layer of particles settles. This process repeats, with more and more layers being settled on top of previous ones. Higher layers exert a force known as overburden on the lower layers, which results in physical and chemical changes to the lower layers. This results in the formation of clastic rocks. Examples of clastic rocks include sandstone and shale.
Biochemical rocks are formed in much the same way as clastic rocks, but from marine life remains rather than particles. Objects such as shell fragments, corals and animal skeletons make up biochemical rocks. Once again, layers of these objects build up, and overburden causes changes to the physical and chemical properties. Examples of biochemical rocks include limestone, chalk and dolomite.
When we talk about reservoirs, it’s easy to imagine a big hole full of fluid. But oil reservoirs are not formed like this at all. Oil is held in spaces between sedimentary rock particles, and these spaces which hold the oil are known as pore spaces. The number of pore spaces, or the porosity of the rock, is an important feature of your reservoir. A higher porosity means more oil.
Another feature of the sedimentary rock which is important when extracting oil is the permeability of the rock, or how well connected the pore spaces are. A higher permeability level means the oil is easier to extract, as it flow more easily through the rock.
The actual formation of the oil itself is not known, but the most widely supported theory is the organic theory. This theory summarises that organic remains, such as those of small plants or animals, where covered by rock deposits and sealed from the air. Over time, the compression of these remains led to changes in the physical and chemical structure of the organic remains, leading to the formation of oil. It is very similar to the formation the sedimentary rocks described above. However, oil doesn’t stay in one place. The place it forms in is known as the source rock. The oil then migrates to the reservoir rock, which is where we extract it from. On top of the reservoir is a rock layer called impervious rock – the oil cannot travel past this layer. The petroleum reservoir accumulates under this rock layer.
Here is a simple diagram of a reservoir as described. Of course in reality things are a bit more complex, but you get the idea!
Activity: Understanding Sedimentary Rocks
You will need:
2-4 containers (empty yoghurt pots or plastic cups work well)
Some dry sand
Oil (cooking oil works well, or light machine oil)
Take your sand and place it into one of your containers. Fill another container with water. Now, take the container filled with water and slowly pour some into the container of sand. What happens?
Answer: The water disappears into the sand. Sand has spaces between its grains too small to be seen by the human eye, and the water is being held within these. This demonstrates how oil is held in the pore spaces in a sedimentary rock.
Note - coarse sand or grit, free from mud and clay, work best here.
Fill one of your containers with water, and the other with a small layer of oil (no more than ¼”). Place your sand or grit into the container with oil. Pour water over your grit until there is a visible water layer on the surface, and leave overnight. What happens?
Answer: There should be a film of oil on the surface of the water. This demonstrates the permeability of sedimentary rocks, and how the oil migrates through the rock to the surface.
How do we find oil?
The first step in extracting oil from it’s reservoirs is to find it. There are several methods for doing this. For land based reservoirs, it can be easier to spot. Faults, domes and other structural contours can be seen at the earth’s surface. An aerial survey may be used to identify these contours on a larger scale. Once a potential reservoir is identified, a field survey will be carried out by geologists on the ground to identify if oil is present. This field survey will look at the shape of the contour or the rock type in the area to see if it fits the profile of an oil reservoir.
For underwater reservoirs, it’s usually more difficult to see contours on the seabed. So visual surveys and field surveys may be undertaken by scuba divers, or a sonar survey (reflected sound waves) can be used to map the seabed.
Prior to drilling into a potential reservoir, a geological survey is carried out to provide some confirmation that the contour is indicative of a reservoir. These surveys can also provide hints as the how deep down beneath the Earth’s surface the reservoir is. A seismic survey is commonly used, and this involves sending a shock wave from the surface of the earth and down through the rock layers below. At the boundary of each layer of rock, part of the wave is reflected back to the surface. This returning wave is picked up by either a geophone (on land) or hydrophone (on water). The returned waves are analysed by computers, which can build up a good picture of the rock layers below. Using this information, the best drilling site can be identified.
Once a drilling site is identified, a well can be drilled using a rig. An exploration well is drilled to see if oil is present as expected. And if we find oil, the real production begins! Once a well is drilled into the reservoir, the oil begins to move up the wellbore to the surface. This oil is collected, stored, and transported to a refinery for processing in the first step for creating all the useful products it is used for.
Rachel Meacock is an environmental consultant working within the energy industry. She obtained an undergraduate bachelors degree from the University of Aberdeen in Marine Biology, and a masters degree in Marine Planning for Sustainable Development from Heriot Watt University’s Orkney campus. Her professional interests involve sustainable offshore development, protection and conservation of the marine environment, and marine planning policy.
Outside of work she is a regular beauty pageant competitor, currently holding the Ms Aberdeen Saltire 2020/21 and Ms Crown and Glory Aberdeen 2021 titles.
Rachel uses the platform her pageant titles give her to inspire more young girls and women to get into scientific fields.
Our Oceans and Seas
Did you know that Seawater covers two-thirds of the Earths surface!
That is a lot of water.
Can you name all the oceans?
Have you ever wondered why the oceans are salty?
This is caused by runoff by salts and other minerals from rocks on land. The rain lands on the rocks and slowly erodes the rocks and they are carried away by rivers and streams, eventually reaching the oceans.
Some of it also comes from the cracks on the seafloor we were finding out about earlier.
We have already learned a lot this week about the ocean floor and what's going on down there when the plates move but what about the actual oceans?
If you had a mini submarine-like in the video earlier in the week what do you think you would find? What would you go looking for?
Do you think there are some creatures still to be discovered? In actual fact, we have only explored around 5% of the world's oceans. We know more about the moon and mars!
The reason for this is they are so deep in some places that it is too dangerous to dive to those depths.
Can you think of a way around this? What could be invented to allow man or machine to explore the deep ocean floor!
What about underwater drones? Is there such a thing?
Check out this video, if you are brave enough, and find out about the most dangerous creatures in the oceans. Warning - it is quite scary!
There are many creatures living in our own seas - have a look at this link - which do you like best?