of Mexico from June to October and affect Mexico and Central
America; continental influences cause climatic uniformity to be much
less pronounced in the eastern and western regions at the same
latitude in the North Pacific Ocean; the western Pacific is
monsoonal--a rainy season occurs during the summer months, when
moisture-laden winds blow from the ocean over the land, and a dry
season during the winter months, when dry winds blow from the Asian
landmass back to the ocean; tropical cyclones (typhoons) may strike
southeast and east Asia from May to December

Terrain: surface currents in the northern Pacific are dominated
by a clockwise, warm-water gyre (broad circular system of currents)
and in the southern Pacific by a counterclockwise, cool-water gyre;
in the northern Pacific, sea ice forms in the Bering Sea and Sea of
Okhotsk in winter; in the southern Pacific, sea ice from Antarctica
reaches its northernmost extent in October; the ocean floor in the
eastern Pacific is dominated by the East Pacific Rise, while the
western Pacific is dissected by deep trenches, including the Mariana
Trench, which is the world's deepest

Elevation extremes:
lowest point: Challenger Deep in the Mariana Trench -10,924 m
highest point: sea level 0 m

Natural resources: oil and gas fields, polymetallic nodules, sand
and gravel aggregates, placer deposits, fish

Natural hazards: surrounded by a zone of violent volcanic and
earthquake activity sometimes referred to as the "Pacific Ring of
Fire"; subject to tropical cyclones (typhoons) in southeast and east
Asia from May to December (most frequent from July to October);
tropical cyclones (hurricanes) may form south of Mexico and strike
Central America and Mexico from June to October (most common in
August and September); southern shipping lanes subject to icebergs
from Antarctica; cyclical El Nino phenomenon occurs off the coast of
Peru, when the trade winds slacken and the warm Equatorial
countercurrent moves south, killing the plankton that is the primary
food source for anchovies; consequently, the anchovies move to
better feeding grounds, causing resident marine birds to starve by
the thousands because of the loss of their food source; ships
subject to superstructure icing in extreme north from October to May
and in extreme south from May to October; persistent fog in the
northern Pacific can be a maritime hazard f