Who first announced his belief that the world is round?
What is magma?
Molten material below the earth's crust
Of what does the Earthâ€™s inner core consist?
Nickel and iron, probably molten.
Approximately what percentage of the Earth's surface is water and what percentage is covered by glaciers?
75% and 10% respectively
Why does an object weigh a little less at the Equator that at the Poles?
Gravitational pull is greater at the Poles that it is at the Equator.
Why does one lean forward when climbing a hill?
To keep the center of gravity of the body as close as possible to the walking base
Where and what is the 'Ring of Fire'?
It is the zone of earthquake epicenters surrounding the Pacific Ocean.
Which is the world's largest volcanic crater?
Mount Aso (1,590m.), which is on Kyushu, Japan.
Where is the North Magnetic Pole?
Located in Prince of Wales Island, Canada in the Arctic Ocean.
Who was the first person to sail north of the North Magnetic Pole?
William Edward Parry in 1819, British explorer and young naval officer.
What causes tides?
The gravitational pull of the Moon and to a far lesser extent that of the Sun.
What is tsunami?
A huge sea wave caused by an earthquake on the ocean bed or occasionally, by a hurricane.
What are the 'Horse Latitudes'?
Sub-tropical belts of high atmospheric pressure over the oceans between the Trade Wind and the Westerlies.
Which clouds are composed mainly of ice crystals?
Cirrus clouds having an altitude of approximately 6,096 â€“ 12,192 m.
For what would one use a hygroscope?
To measure the humidity in the air.
What is meant by an alluvial plain?
The flat land bordering a river, formed of alluvium (sand & silt) left by the river.
What is an aurora?
Shimmering curtains of light in different colors in high altitudes in the Arctic and Antarctic regions.
What is the continental shelf?
The seabed, bordering the continents that form the boundary of the ocean basins.
What is a 'cold desert'?
The 'cold desert' is the ice sheet of the Arctic and Antarctic regions.
What is a savannah?
It is a grassland with scattered trees, grading to either plain or woodland in tropical and sub-tropical countries.
What are the tundra areas of land?
North America and northern Eurasia mainly along the Arctic circle. For most of the year temperatures are below freezing point.
What is a watershed?
The elevated boundary line separating the headstreams to different river systems or basins.
What is geothermal energy?
Natural thermal energy of the Earthâ€™s interior.
What is the second major energy source after oil?
What is the 'snowline'?
It is an altitudinal line above which it is too cold for snow to melt even in the summer.