A landslide generally refers to “the movement of a mass of rock, debris or earth down a slope”
http://www.whitman.edu/environmental_studies/WWRB/nyborgthesis.htm
Where the rock below the land surface is limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by ground water circulating through them.
http://ga.water.usgs.gov/edu/earthgwsinkholes.html
If the salt in the sea could be removed and spread evenly over the Earth's land surface it would form a layer more than 500 feet thick, about the height of a 40-story office building
http://www.palomar.edu/oceanography/salty_ocean.htm
The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air.
http://www.sciencemadesimple.com/sky_blue.html
Observe and record the wind direction.
http://www.tryscience.org/experiments/experiments_windbubbles_athome.html
Climate varies in distinct patterns around the globe enabling scientists to describe numerous climatic zones
http://parentingteens.about.com/cs/homeworkhelp/l/blscpro35.htm
Climate varies in distinct patterns around the globe enabling scientists to describe numerous climatic zones
http://parentingteens.about.com/cs/homeworkhelp/l/blscpro36.htm
Climate varies in distinct patterns around the globe enabling scientists to describe numerous climatic zones.
http://parentingteens.about.com/cs/homeworkhelp/l/blscpro34.htm
Clouds are a visible body, usually white or gray, of fine water droplets high in the earth's atmosphere.
http://parentingteens.about.com/cs/homeworkhelp/l/blscpro4.htm
The earliest archaeological site in Ireland that we know about is called Mount Sandel, near the River Bann in County Derry.
http://archaeology.about.com/library/sf/blsc_irish.htm