The structure of the Earth
 | Imagine a Scotch egg......
The deepest anyone has drilled into the earth is around 12 kilometres, we've only scratched the surface. How do we know what's going on deep underground? |
| There are lots of clues: |
Welcome, to a world of the Past, the Present, and the Future. Have you been wondering about the fascinating features of Nature?. Have you ever so badly wanted answers to your questions about Evolution?, then you are on the right track. Welcome to a world where Primates and their environment are filtered by the cameras of Science. Welcome to a world of "ANTAEOLOGY"
Friday, 19 December 2014
A Timeline of Earthquakes that have graced Earth
3600BC The Supe people, a maritime farming community along the coast of Peru, disappeared about this time. In 2009 researchers found their disappearance coincided with earthquakes and landslides followed by massive flooding.
(SFC, 1/20/09, p.A13)
373BC The Greek city of Helike was destroyed by an earthquake. Historians recorded that rats, snakes and weasels had abandoned Helice just days before the quake struck.
(NH, 10/02, p.78)(WSJ, 5/16/08, p.A6)
360BC Greek philosopher Plato, in his "dialogues" from about this time, said an island he called Atlantis "in a single day and night... disappeared into the depths of the sea." He described Atlantis as "an island situated in front of the straits which are by you called the Pillars of Hercules." In 2011 a US-led research team, using a satellite photo of a suspected submerged city, suggested a site just north of Cadiz, Spain, as the site of Atlantis.
(Reuters, 3/12/11)
27BC An earthquake hit
EVOLUTION IN PERSPECTIVE
Evidence of Evolution
The Nobel Prize winning scientist Linus Pauling aptly described science as the search for truth. Science does this by continuously comparing its theories objectively with evidence in the natural world. When theories no longer conform to the evidence, they are modified or rejected in favor of new theories that do conform. In other words, science constantly tries to prove its assumptions to be false and rejects implausible explanations. In this way, scientific knowledge and understanding grow over time. Religious explanations for the order of things are not science because they are based primarily on faith and do not subject themselves to be objectively falsified. Because of this fundamental difference in the approach to understanding our natural world, the U.S. Supreme Court in effect decided in 1987 that the Biblically based "creation science" is not a science and cannot be taught as such in public schools as an alternative or in addition to the mainstream evolutionary theory of the biological sciences. However, religious creation stories and the idea of "intelligent design" can be taught in philosophy, religion, or history courses. Religion and Science provide different approaches to knowledge. It is important to understand both.
Biological evolution is
What Is Evolution?
- A volcano is a mountain that opens downward to a pool of molten rock below the surface of the earth. When pressure builds up, eruptions occur.
- In an eruption, gases and rock shoot up through the opening and spill over or fill the air with lava fragments. Eruptions can cause lava flows, hot ash flows, mudslides, avalanches, falling ash and floods.
- The danger area around a volcano covers about a 20-mile radius.
- Fresh volcanic ash,
HOW TO MAKE BUILDINGS AND STRUCTURES EARTHQUAKE-PROOF
There are a wide variety of earthquake effects - these might include a chasm opening up or a drop of many metres across a fault line. Therefore, it is not possible to design an earthquake proof building which is guaranteed to resist all possible earthquakes. However, it is possible during your design and construction process to build in a number of earthquake resistant features by applying earthquake engineering techniques, which would increase enormously the chances of survival of both buildings and their occupants.
What is an earthquake?
Both the seabed and the land that we inhabit are formed of a crusty skin of light rocks floating on the soft centre of the earth, which is made of heavier molten rock and molten iron. This crusty skin is not one solid piece but is made up of lumps, separated by faults and trenches, or pressed together into mountains. These separate lumps and plates are not static but are moved in slow motion by convection forces in the molten core, gravitational forces from the Sun and Moon and centrifugal forces from the Earth's rotation. Some plates are moving apart, particularly in the Mid Ocean Trenches, where molten material pushes up and shoves the plates apart, whilst others are bumping into each other head on, these form mountains like the Himalayas (the whole of the Indian Sub Continent is moving northwards and hitting Asia, for example). Some are sliding one over another, like the west coast of the Americas, where the land plates are sliding over the denser ocean bed plates, causing the Andes and the Rockies to be thrust upwards. Some plates are moving along past each other, sticking together a while at a fault line, often in combination with bumping or sliding under/over (As in San Francisco).All of these movements cause earthquakes (and usually volcanoes as well). If the movement was steady, about a millimetre or so a year, no one would notice. But the plates tend to jam; the movement carries on, but the material where they touch is stretched, or compressed, or bent sideways. The material deforms (like stretching or compressing or twisting a bit of plastic). At some stage it reaches the breaking point along all or part of the joint, then it breaks, and there is a sudden movement. The movement may be tiny or may be several feet; but enormous amounts of energy are released, far more than the biggest Nuclear Bombs. The shock waves from this release of energy shoot out in all directions, like the ripples when you throw a stone in a pond: except that they travel faster through the land. They can be measured all around the whole world. This is an Earthquake.
Prior to the Earthquake there are often little warning shakes, where highly stressed bits break and the plate joints readjust themselves a little, but allow the main join to become more stressed. After the primary Earthquake when the main join has failed and moved, there is another readjustment, and further bits around the fault become overstressed too, and they fail. These aftershocks can themselves be highly energetic Earthquakes. After the Earthquake, the area settles down again. But the movement carries on and the next Earthquake is already building up, remorselessly. People forget and build buildings and structures that are going to kill their children next time when they could ensure that during the design and construction phase some earthquake proof measures have been incorporated.
What makes a building or structure fail in earthquakes?
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