Sex, Drugs, and Public Health

May 28, 2015

BLOG from the Sea of Cortez 4 – Antarctica

Filed under: Uncategorized — cbmosher @ 12:53 pm

Baja California  –  A Different Antarctica

North: The leading edge of the North American Plate scrapes up the sea floor of the Pacific Plate. Mantle rocks, metamorphed, crumple to the surface. The volcanoes of Baja vent the energy. Pink pyroclastic flow welds to the mantle’s serpentine, and gray mud flows down the flanks of the Three Virgins volcanoes to create plains.

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South: Beneath the ice dome – 13,000 feet thick in some places – the rock continent of Antarctica has also spawned living volcanoes. Mount Erebus on Greater Antarctica is still active and steaming, and more recently, an active volcano has been discovered beneath the ice.

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North: Scraggly succulents cling to the rock and sand of Baja – a landscape predominantly barren. There are rare oases of pine in deep valleys where seasonal rains briefly collect. Salt-tolerant mangroves line estuaries where the water evaporates, increasing its salt content. A few animals can survive here: scorpions, snakes, coyotes, the rare mountain lion.

South: This continent, one and a half times the size of the U.S., is all rock. Some of it so laden with minerals that its dust is sterile – not even appropriately called “soil.” On the slightly richer land of the Peninsula, algae, lichen and mosses compose most of the life. There are only two species of vascular plants, neither taller than 1.5 inches.

Animals? Tiny insects only.

North: The roads of Baja, piercing the sand and rock, occasionally cross surprisingly long bridges. No water flows beneath them, but wide swaths of violent erosion snaking down from the Sierra, slithering beneath the bridge, and out into the Sea are evidence of seasonal flash flooding.

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South: The rivers of Antarctica follow a different time frame – they are always present, always flowing, always frozen, always eroding.

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North: Baja, of course, is a desert. Annual rainfall just 8.5 inches at LaPaz.

South: Falling onto the great dome of ice which contains 70 % of the entire fresh water supply of Earth, is less than 5 inches of water a year. As snow, of course. A drier desert than Baja.

Both places are famous for their hostile weather. Katabatic winds sweep down on the Sea of Cortez from between the peaks of the Sierra like the Hashishans of Afghanistan. They attack in the night, blowing hard and swirling, confusing sailors who must pick a protected anchorage. Often, the wind will shift 180o at night, frustrating such attempts.

The katabatic winds of Antarctica, gaining velocity as cold, dense air sinks down from mountain peaks buried by ice to a height of 13,860 feet, can reach 150 m.p.h. by the time they scour the glaciers. These dry, cold hurricane-force winds have stripped entire valleys of their snow, ice and soil.

The most dreaded of Mexican weather – hurricanes (aka Tropical Cyclones) – have never achieved such velocities, but are powerful enough to have shredded marinas and cities – most recently the resort cities of Cabo San Lucas and La Paz.

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The hostility of these lands to Life is a dramatic contrast to what teems beneath their water.

North: The Sea of Cortez – dubbed by Costeau as “The World’s Aquarium” has over 5000 species of micro-invertebrates which feed starfish, oysters, crabs, lobsters and those edible “locusts of the sea,” shrimp.

Working up the food chain, 900 species of fish prey on the invertebrates, then become prey in turn to hundreds species of larger fish and sea mammals.

Whales are numerous, including the small Minke, bigger-than-dinosaurs Blue, Moby-Dick Sperm, and acrobatic Humpback.

South: A similar, but much simpler food chain teems within the ocean of highest bio-productivity on the planet. The Southern Ocean is just one twentieth of the world’s seawater, but produces one fifth of all oceans’ carbon life forms. Blooms of phytoplankton feed dense explosions of krill. Not a shrimp, we’re told, but sure looks like that crustacean. It feeds fish, squid, penguins, albatross, petrals, seals and even the Humpback whale. One Humpback may swallow up to a ton of krill a day. In this Ocean, such a level of feeding is sustainable.

The whales of Antarctica includes some species familiar to the Sea of Cortez: Sperm, Minke, Blue, Humpback.

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On the frigid seafloor live urchins, stars, worms, and other colorful invertebrates. Different species, but similar life forms to the warm Sea thousands of miles north.

Predators: the Sea of Cortez (aka Gulf of California or the Vermillion Sea) hosts several species of shark, including the Hammerhead. Eight hundred pound Sea lions prowl.

The Southern Ocean is stalking grounds of the Leopard Seal, similar in weight to the Sea Lion. He’s a no-nonsense hunter whose only match is the Killer Whale.

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South: Of the Southern Ocean birds, the penguin is best known. Appealingly clumsy and anthropomorphic, it reminds us of one year old children learning to walk. But when it hits the water, it’s a well equipped torpedo. Above, albatross with ten foot wingspans (largest of all birds) and heads the size of a man’s drift and hunt. They are airborne most of their lives, seldom flapping their glider wings

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North: No albatross here, but the pelagic piscivore in this ecological niche is the Frigate Bird. Similar in shape, nearly as large as the albatross, he also soars over open water, seldom flapping his wings and never landing on water.

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Pelicans, though not torpedoes like penguins, may well appear to be a water-going missile – for an instant anyway – to a fish too close to the surface.

These two seas, so different from each other in obvious ways and so distant geographically, are nonetheless both crucial to the planet and intimately connected with each other.

The Aquarium of the World, with its deep underwater canyons plunging to almost two miles, is one of the world’s richest fisheries. It can feed a large portion of the people living near it, if we use it wisely, or it can collapse if we continue to abuse it.

The Southern Ocean, and the massive Ice Dome of the continent the ocean surrounds (ironically shaped like a Sea of Cortez stingray), maintain both the planet’s balance of heat and the circulation of all the oceans, including Baja’s Sea.

The albedo of the Ice Dome reflects back 80% of solar radiation, preventing uncontrolled heating, while the very cold, very dense Antarctic Bottom Water, plummeting to the sea floor, drives the circulation of the ocean currents as if it were the planet’s heart.

The Southern Ocean, unlike the Sea of Cortez, is the most pristine of all seas. Protecting its 10,000 species and its role in circulation of the oceans may depend on how well we learn the lessons from the warm Sea to the north.

(photos by me, Sarah Mosher, and Tom Marlow; see also http://ketch-22.com/ )

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