The earth has only very recently been accurately dated. Until astonishingly recently, the earth was thought to be anywhere between a few hundred thousand and a few million years old. Now it is thought that the Earth is 4.6 billion years old, and was formed by interstellar dust coming together and being attracted to an increasingly strong gravitational force. Incidentally, life is thought to have arisen relatively early in the earth's existence - just 3.5 - 4 billion years ago!
2. How many seismograph stations are needed to allocate the epicenter of an earthquake?
Usually the triangulation method is used, making three measurements, and then using simple geometry/maths to locate the positioning.
3. It was a boiling, burning pile of rubble effectively.
Over time it developed an atmosphere that changed in time as liquid water gathered on the surface of the earth and created an atmosphere with clouds of water and levels of certain gases that protected the planet below and made it the temperature that it is, which is obviously fit for life as we can tell by looking around us.
4. How has the earth changed since it was formed?
The earth has changed massively since it was formed. Earth was a ball of rock that was hit and changed by loads of impacts and meteor impacts.
5. How can we calculate or estimate the evaporation from lakes?
Factors such as the volume and surface area of the lake together with average wind speed and temperature at the surface are the factors that can be used to work out how much evaporation there is at the surface.
6. How do we know magma does not originate in the liquid outer core?
Specifically gases that are found in the magma correspond to having been formed at pressures many times greater than those in the outer core have, and rather therefore indicate that it was formed elsewhere.
7. How do minerals become rocks and rocks become soil?
Minerals or small particles of rocks, become rocks through pressure and temperature, often deep inside the earth's core, or simply through pressure for instance on the seabed.
Wherever many small things become something big it is usually through compression, temperature, or pressure.
The opposite process - large things being worn into smaller particles - usually comes through another sort of force. Either weathering, erosion - action by wind, rain, and water - is responsible.
Gradually many rocks are eroded by movement of ice and water over them or the wind action also to become finer and finer and form little grains - e.g. of sand or of soil.
8. How do geologists find out the age of mountains?
Various ways and techniques can be used. With many mountains, the rock in the mountain can be sampled and then a dating technique applied to find the age.
For instance, radiometric dating may be used to find the age of the rock. These techniques exploit the half-life of naturally occurring radioactive isotopes of elements present in tiny quantities to help work out how old something is.
With some mountains other techniques may be used, for instance at a plate boundary scientists may be able to wind back time to work out when the plates must have collided and formed mountain ranges such as the Himalayas.
Limestone is formed from pressure applied over time to dead creatures in the sea. Oil is formed because of sedimentary processes and which is one of the most important resources.
Fossils are created amongst periods of rock formation, and caused by the gradual accumulation of sediment over millions of years at the bottom, most commonly, of the seabed.
11. How are the layers of schist separated into alternating light and dark minerals?
The heat and compression deep within the earth's magma are what cause these unique and interesting layers of striation.
Depending on the particular stresses and strains, heat and pressure applied, and the individual rocks and minerals there in that composed the material, they react differently and this is what causes the banding.
12. Explain how the asthenosphere works?
The asthenosphere is a layer of the earths crust. There are various definitions here is one of them from a geology resources definition list:
"A layer of soft but solid, mobile rock comprising the lower part of the upper mantle from about 100 to 350 kilometers beneath the Earth's surface."
13. Discuss major factors that influence mass movements.
Things as if climate and food availability will make a big difference if it is too cold, too dry then people will need to move.
In addition, the amount of food is important too. Other factors might be human and political ones - such as a tough regime in charge of a country or if there is a war and so on then people will want to move too.
14. Describe the formation of igneous, sedimentary, and metamorphic rocks?
Igneous rocks are formed through volcanic action and because of volcanic activity.
Sedimentary rock takes a long time to form and is dead bits of animals laid down in the sea and compressed over millions of years to form rock; anywhere you see sedimentary rock you are seeing the remains of creatures that were once in the ocean a long time ago.
Metamorphic rock is formed through a combination of heat and pressure inside the earth.
15. Contrast the process that forms igneous rocks with the process that form metamorphic rocks.
Igneous rocks form in quite a different way to metamorphic rocks.
Igneous rocks form due to heat and volcanic activity specifically they form when molten rock cools and becomes solid.
However, metamorphic rocks are existing rocks - perhaps igneous ones - that have been changed by great pressure and often-great heat into metamorphic rocks.
16. How Continental heat flow is produced?
This is caused by the magma - the molten rock - that is underneath each of the plates of the earth and causes them to move and flow along.
This is the major cause of this phenomenon to the best of our current geological understanding.
17. Describe the formation of igneous, sedimentary, and metamorphic rocks?
Igneous rocks are those that form from volcanoes and volcanic activity.
Sedimentary rocks are laid down over great time in oceans and are the results of compression on dead organic matter like small sea animals and so on.
Metamorphic rock is a change that occurs to igneous or sedimentary rock in the earth's crust due to the immense heat and pressure there acting on those rocks and chemically and physically changing their properties.
18. How were sedimentary rocks created?
Sedimentary rocks have a clue to their origin in the name - sediment.
They are the products of lots and many dead marine creatures, which piled up on the sea floor as they were formed in water. These piled up together over a period and the pressure of them all caused the formation of rock.
19. In 1763, how did Great Britain try to end troubles with the Native American?
By offering more rights and giving better treatment, more freedom and better options it was hoped to reduce the conflict and pre-empt problems from occurring because of this.
20. What did Radon detection in arid areas can help to explore?
Radon is a radioactive gas that is associated with certain rocks, so perhaps this is a measure of the geology of the area, as in the rocks that are present in that location?
21. Soils take how many years to form?
There is no answer to this as it varies very much depending on the type of soil you are talking about and the conditions on earth at the time.
In places that are very warm or very wet with fast moving waters for instance then times are quicker than places where very little happens for thousands of years at a time.
However, the process is very slow indeed and therefore, you would be looking at hundreds of years to produce an inch of soil - and 1,000 years+ to get two or more inches.
22. Were there super continents before pangea?
Pangaea is used to describe the state where all the land on earth was one great big landmass and therefore there was just one ocean too which was everything that surrounded that land mass.
Therefore, before Pangaea or all the land was linked you are asking whether the land was previously split before it came together. That is possible - we do not know the answer. However, we read about it and current theory suggests that yes there have been break ups and come together forming super continents before, though this hardly seems set in stone.
23. What are examples of techno fossils?
In which case I guess that you might be referring to things such as nuclear waste and other waste products of our recent systems for instance rubbish dumps and similar.
We have also fired some artifacts into space, for instance on spacecraft that aliens might some time come across we have given a glimpse or snapshot of our lives at a particular time in history.
24. What are the three major types of rocks?
The three types of rocks are as follows:
1) Igneous (from volcanoes etc)
2) Sedimentary (Dead Sea creatures, time and pressure)
3) Metamorphic (other rock types compressed, squished, heated and geologically stressed in massive temperatures and pressure fairly deep in the earth)
25. What does a Geologist do on a typical day?
One in academia for instance will spend the day doing research and writing papers and lecturing.
Others will be involved in practical work in the field, examining rocks and structures and making deductions about age and formation and so on.
