Social Science : Geography
VI. Distinguish the following
• When the Sun, Moon and Earth are aligned in the same line, the collective gravitation pull of the sun and moon on earth's water strengthens to form a high tide known as spring tide.
• Such tides always occur on full moon and new moon days.
• When the Sun and the Moon are at right angles, their gravitational forces work against each other, causing a low tide called neap tide.
• A neap tide occurs between two spring tide i.e, twice a month, when the first and last quarter moon appears.
• These are underwater plains found on the deep ocean floor.
• These are usually covered by the thick layer of sediments composed of clay, silt and sand, brought by the rivers.
• These gradient of the slope is veiy gentle and it appears as a uniform flat and featureless plain.
• These are the deepest part of the oceans.
• They are sediment free.
• Most trenches are V-shaped with steep sides.