Summer Science | National Geographic

like all seasons summer is the result of
an astronomical fact of life
the earth is tilted on its axis 23 and a
half degrees as the planet moves in its
yearly orbit that angle comes as the
position of the northern hemisphere to
change relative to the Sun in the winter
it’s tilted away from the Sun in the
summer it angles towards the center
because of the planets tilt during the
summer sunlight hits the earth at a more
direct angle so the warming effect of
the sunlight is more intense plus the
Sun is at its highest point in the sky
so there are more hours of sunlight to
provide heat the opposite is true for
the southern hemisphere where the
seasons are reversed when we’re angled
toward the Sun they’re angled away so
while our Australian friends chill out
in winter we’re headed for the beach
there is some amazing science behind how
that golden strip of sand is created
the sand on most beaches begins not in
the ocean but inland over time
weathering by ice wind and rain breaks
down rock into sediment creeks and
rivers wash the sediment downstream
once in the ocean currents of water
called longshore currents that flow
parallel to the coast carry those
sentiments along the shoreline waves
then push the sand onto Shore forming
beaches longshore currents can deliver
up to a million cubic yards of sediment
to a single Beach each year
most waves that deliver sand to our
beaches are born thousands of miles away
ocean waves are created basically by the
wind the wind blows across the surface
of the water and it agitates the surface
of the water causing a wave to be formed
the longer the wind blows or the
stronger the wind blows the bigger the
wave that’s going to create waves are
generated by wind blown across the
surface of the ocean energy from the
wind is transferred to the wave through
friction between the air and water wind
that blows faster longer and further
will transfer more energy into the ocean
and create bigger waves waves sometimes
travel across vast expanses of open
ocean in some cases as far as 10,000
miles waves can travel across entire
ocean basins so a very strong storm in
the southwest Pacific will create a
swell which could go all the way across
the Pacific Ocean and end up impacting
Mexico or the west coast of North
America