Why rocks on building rooftops?
609488
Protect the tar/membrane system from sun/uv, and reflect sun to keep temps lower. Also, weight prevent wind damage to membrane system. Very good roof, long lasting, relatively inexpensive to install.
560451
Because shale is sedimentary and basalt igneous. Which is to say that shale is laid down by silt which hardens into a soft rock over centuries and basalt is the result of heat and volcanic eruption. Obviously silt doesn't settle in places where volacanoes are going off.
652500
Answer A) Small size & rocky surfaces
852815
Probably because they are round and keep moving, bumping into each other. Confusing is; when they bang together, pieces never fall off OR they get smaller with friction.
675396
Cause a brick might fall on your feet.
885157
There are lots of insulating materials made for this job.  fibreglass batts are the most common but you could also use blown in insulation which is made from ground up newsprint. or styrofoam sheets or spray on expanding insulation which is the best because it gets in all the cracks but it is also the most expensive. On some flat roofs the insulation goes on the outside and the roofing material goes over it but in most houses with a pitched roof the insulation goes over the ceiling and this leaves an air space between the insulation and the roof.  Its very important to have proper ventilation in this area to carry away any moisture that may get there.
850784
Its asking what rock types (lithologies) would form topographical highs. in other words which rock type would weather away and which would stay longer. the ones that stay will be your topographical highs.
247030
thats an igneoous rock. dont know where to get one though
74001
When the "Big One" hits LA, it is very possible that small (less than 1 square mile) portions of the cliffs from Santa Monica to Malibu may fall in the ocean, but NO catastrophic (i.e. a city-wide or state-wide collapse) can possibly occur.  The primary reason is that all rocks have a finite strength and ability to accumulate stress.  Rocks along any fault will fail (causing an earthquake) before they can accumulate the amount of stress required to generate an earthquake capable of causing anything outside a mile or so of the coast to fall into the ocean.  That is the reason you don't see earthquakes greater in magnitude than 9-9.5....because rocks break and release their energy in the form of an earthquake before they can accumulate the stress required for a magnitude 10 or greater.
1050564
well city has tons of buildings and the buildings have weight. so they will add more pressure to the tectonic plates and cause them to move faster i guess. There are tectonic plates which meet at one point and they either slip, slide or grind agaisnt each other. and when they slip, this causes the earthquake. so then the more weight on the plates means also more pull. so the plates move faster or something. my guess. but i doubt it has any effect
70473
Scree is one word that describes a pile of loose rock, but it isn't specific to rock at the base of a mountain. \n\nA much better anwer would be "alluvial fan". This is the specific name given to rock that slides down off of mountains and forms wedge shaped piles at the base.
527140
Probably something lighter than steel since you have to ship it up there.   I'm not sure what the surface of mars is made out of.  If its made out of rock you probably don't need much of a foundation at all.  If it is made out of mud or sand you'l likely need to have a long wide plate that will distribute the load of your building over a larger area.
88067
probably to put up a taller building
223795
Spheroidal weathering\nFrom Wikipedia, the free encyclopedia\nJump to: navigation, search\nSpheroidal weathering is a type of physical and chemical weathering that creates rounded boulders and helps to create domed monoliths. This should not be confused with stream abrasion which also creates rounded rocks on a much smaller scale. A good example of spheroidal weathering can be found in the Alabama Hills area of eastern California.\n\nSpheroidal weathering occurs whenever a mass of rock (most typically granitic in composition), experiences a drastic reduction in ambient heat and pressure, such as when a batholith is exposed at the surface. Rock forms at great temperatures and pressures (760 °C and 300 MPa)|atm.]] for granitic rock), and in granites there are three mutually perpendicular sets of joints that develop when this overburden is removed. Two things cause this in granites: the quartz crystals expand about 5%, and acidic water attacks the feldspar minerals, turning them into clay. Thus the corners become rounded, because angular edges provide more than one area of attack by exposing a greater amount of surface area. Edges and especially corners of an angular block weather faster than flatter surfaces. The ultimate result of this process is a rounded bolder or a domed monolith such as the rounded back of Half Dome in Yosemite National Park.\n\nThe process of spheroidal weathering is slower than other common types of weathering such as frost wedging, and it becomes lower still at progressively lower temperatures which slow down the chemical process of feldspar breakdown. Thus many granitic mountain peaks are jagged and craggey instead of rounded.
248396
OMGGG!! I can go on forever on this one... but I'll try to be as brief as possible. \n\nOk, so rocks are made by three different processes: \n\n- Volcanic eruptions - These rocks are called IGNEOUS ROCKS.  There are various types of rocks that can be produced.  They can be from either when lava flows on the surface of the earth and cools down, or when magma inside a volcano cools down before it hits the surface.  It doesn't take all that long for these types of rocks to form, and hese rocks are usually crystallized and can be easily distinguished because of the crystal type of formation.\n\n- Another tyoe of rocks - called SEDIMENTARY ROCKS are a result of erosion by wind, water, or glaciers.  These types of rocks may take thousands or even millions of years to form.  So, in this process, sediment (the tiny particles) that is eroded away from the different erosion processes settle in one place and over a long period of time they are formed into rocks. One layeer after the next. \n\n- And the last types of rocks are formed from either Igneous rocks or Sedimentary rocks.  These are called METAMORPHIC ROCKS... word derived because thise rocks have "morphed" into something that is no longer sedimentary or igneous rocks.  These rocks go through these changes and become Metamorphic due to the high pressure which causes heat to build up in these solids.  These rocks can also be relatively easily distinguished because when you look at them, you can actually see flat grains.\n\nso, no! Rocks do not magically appear but they appear over time.  \n\nThere is tons more to the subject, as in you can actually study a given rock and tell how old it actually is and when it was originally formed, but that's another question! :)\n\nhope this helped... \nCheers!
814798
Mostly flexible structures.\nBuildings that are built to bend or move with the tremors, Bridges that can twist. If the structures can flex then they do not break (Cocktail stick versus rubber band). Some buildings collapse when they resonate (vibrating in tune with the earthquakes) Building designers can use different materials or different designs to stop resonance. Round buildings instead of square, thicker or thinner walls or make buildings modular ( like bricks stacked on top of each other.
467968
Sedimentary rock forms relatively flat. Youngest always on top of the oldest. Just like a stack of newspapers if you were to accumulate them everyday.\n\nFolding from compressional stress is one. Rock is literally pushed together creating anticlines & synclines, upward folding & downward folding arches respectively.\n\nFaults can also do this. This can be accomplished through compressional (pushed together) or tensional (pulled apart) stresses.\n\nI am not too sure about this one but isostatic adjustment could possibly tilt rocks.\n\nHope this helps.\n\n:)