The Congo River

Almost 3000 miles long and second only to the Amazon in its annual flow volume, the Congo River curves counterclockwise through the Democratic Repbulic of the Congo, taking in tributaries from a watershed that exceeds 1.5 million square miles.  The Upper Congo, known as the Lualaba River, receives the Luvua River from Lake Mweru, on the Zambian border, and flows northward, gathering the waters of other streams from Lake Tanganyika, to its east.  Alternately placid and turbulent, the Lualaba reaches Kisangani following a sixty mile course of rapids known as Boyoma Falls (formerly Stanley Falls).

From Kisangani to Kinshasa, at the west end of the Malebo Pool, the 1000 mile stretch of the Middle Congo is wide and navigable, receiving large tributaries such as the Lomami, from the south, the Aruwimi, from the east, and the Ubangi, from the northeast; just upstream from the calm, deep Malebo Pool, the Kasai River enters from the southeast.  Below Kinshasa, Livingston Falls, 90 miles of rapids and cataracts, make the Congo unpassable once again; to bypass this stretch, the Matadi-Kinshasa Railway was constructed in the 1890s.  From Matadi to the Atlantic Ocean, the river is broad and navigable and its braided delta begins just west of Boma; the Congo's total elevation drop, from Lake Mweru to this delta, is just over 3000 feet.

Crossing the equator twice and winding through the second largest tropical rainforest on our planet, the Congo evokes a sense of adventure, mystery and hidden danger.  Long before humans tainted its name with the atrocities of colonialism and slavery, this mighty river nourished and cleansed the Heart of Africa, connecting its lush savannas and dense forests to the distant sea; that role will surely continue long after we have plundered the natural bounty of our native Continent.

Madagascar's Cyclone Season

Madagascar, the fourth largest island on Earth, lies off the southeast coast of Africa, in the western Indian Ocean. Oriented northeast to southwest, the island is bathed by southeasterly trade winds throughout the year, producing copious precipitation along its eastern coast; indeed, some areas receive up to 150 inches of rain. Since highlands run down the center of the island, the western coast of Madagascar lies in their rain shadow and its climate is much drier.

The wet season in Madagascar runs from November through April, encompassing the warmest months of the year. During the Southern Hemisphere summer, the Intertropical Convergence Zone (ITCZ) drifts south from the Equator and, from December through early March, it crosses the northern half of Madagascar. Along this zone, northeasterly and southeasterly trade winds merge, producing lift and bands of thunderstorms; the colliding winds also produce wind shear at the surface and, if upper level winds are calm, cyclones may develop. Most common from January into March, those that strike Madagascar develop east of the island, over the warm waters of the Indian Ocean, and then drift westward along the ITCZ.

This week, Cyclone Giovanna, a category 4 storm, packing winds up to 120 miles per hour, has produced devastation across the island nation, killing at least 5 persons. After crossing Madagascar, it is expected to impact Mozambique, on the African mainland.

A New Canary Island

The Canary Islands are a volcanic island chain off the northwest coast of Africa. Current geologic evidence suggests that this Spanish archipelago developed (and continues to form) above a mantle plume, commonly known as a hotspot. Erupting through Jurassic oceanic crust that formed as the Atlantic Ocean opened, 150 million years ago (MYA), the base of the oldest islands began to take shape during the Cretaceous Period, some 80 MYA, and finally emerged from the sea during the Miocene Period, about 20 MYA. Mt. Teide, 12,200 feet, rises on the island of Tenerife; the highest peak in Spanish territory, it is also the third tallest volcano on the planet.

The Canary archipelago stretches for 500 km, aligned ENE to WSW; the oldest islands, just 100 km off the African coast lie at the northeast end of the chain while the youngest island, El Hierro, just 1.2 million years old, is at the southwest end of the island group. This past summer, earthquake activity began to increase on El Hierro as a new island grew just 7 km off its southern shore; now less than 70 meters from the surface, the newest Canary island spews seawater and volcanic debris into the air and threatens communities on El Hierro with the potential of an explosive eruption.

Like the Hawaiian Ridge, which has developed as the Pacific Plate moves to the WNW across a mantle plume, the Canaries are high points on a volcanic ridge that has formed as the Atlantic province of the African Plate is moving ENE above a similar hotspot. As a new Hawaiian island forms off the southeast coast of the Big Island, a new Canary Island appears at the southwest end of its parent archipelago.

The Albertine Rift

The East African Rift is the southern end of a rift system that extends from the Jordan Valley of the Middle East to the coast of Mozambique. Active for the past 40 million years, the rift will eventually split the Continent, opening a sea between the primary land mass, to the west, and a smaller segment to the east. In east-central Africa, a 750 mile-long western branch of this rift system, known as the Albertine Rift, harbors a chain of lakes: from north to south, these are Lakes Albert, Edward, Kivu and Tanganyika.

The Albertine Rift is bordered by six mountain ranges along its corridor; the most famous are the Virunga Volcanoes, northeast of Lake Kivu, and the Rwenzori Mountains, NNE of Lake Edward. The Virungas, home to critically endangered mountain gorillas, lie on the border of Rwanda and the Democratic Republic of Congo (DRC); capped by Mt. Karisimbi, 14,790 feet, the Virungas formed within the rift and are slowly moving to the east. The Rwenzori Mountains, along the border of DRC and Uganda, are a fault-block range that rose during the Pliocene (about 3 million years ago) and were sculpted by mountain glaciers during the Pleistocene; even today, this massive range of Precambrian rock, capped by Mt. Stanley (16,760 feet), has permanent snow fields in the heart of the tropics. The Rwenzoris lie at the west edge of the Albertine Rift and are gradually moving to the northwest.

Volcanoes National Park protects the Virungas within Rwanda while Rwenzori Mountains National Park lies just within Uganda; Virunga National Park, established in 1925 (the first in Africa), lies in the DRC and stretches along the Albertine Rift Valley between the Virungas and the Rwenzoris. Once home to a spectacular diversity of plant and animal life, these Parks are slowly recovering from the devastation of human conflict that occured throughout the late 20th Century.

Wall Street & Somalia

Tuning into the PBS News Hour last evening, one of the few television shows of any value, I watched two stories that highlighted the vast and growing gulf in human society. The first focused on the meltdown in the stock market, triggered by upperclass tax cuts, futile wars, the banking crisis and recent bickering in Congress over the National Debt. The second, in sharp contrast, revealed the horror in southern Somalia, where a prolonged drought and vicious militias have sent hordes of starving families across the border, to a massive refugee camp in Kenya; some 30,000 Somali children have died from illness and starvation over the past few months.

While these crises are worlds apart, their juxtaposition in the news highlighted the tremendous variance in human lifestyles, a phenomenon unseen in any other species. The comfortable life of an investment banker, with his mansion, penthouse and yacht, is so far removed from that of a starving Somali child that it takes some effort to realize that these two individuals have the same physical and mental potential and the same emotional needs. Unfortunately, due to the inherent selfishness of our species, few are willing or able to acknowledge this basic relationship.

Efforts to encourage a balanced approach to the inequities in human society are met with condemnations of socialism and are strongly opposed by those with the means to initiate significant change. Power, greed, zealotry and selfishness are at the helm and untold millions suffer the consequences. In time, the massive divide between rich and poor must change from within or, as history has demonstrated, revolution will even the score.

Hominids & the Sahara Desert

The vast Sahara Desert, which stretches across North Africa, began to form in the late Miocene and early Pliocene, some 10 million years ago (MYA). South of this geophysical region, gorillas diverged from the hominid line about 9 MYA and chimpanzees followed 7 MYA. By 4.5 MYA, Australopithecus appeared in the Rift Valley of East Africa and, by 2 MYA, Homo erectus had evolved.

While the Sahara may have been a natural blockade to the northward migration of the earliest hominids, the Pleistocene Epoch (2 MYA to 10,000 YA) brought wide swings in the global climate, marked by four periods of glaciation. During these glacial periods, a cool, wet climate caused the Sahara to contract, opening corridors of savannah that likely permitted ancestral hominids to migrate northward, into Eurasia. Following earlier migrations of Homo erectus, Neandertals began to leave Africa about the time that humans were first appearing, some 150,000 years ago, and occupied Europe by 100,000 years ago. Man remained in sub-Saharan Africa until about 60,000 years ago, when the Wisconsin glaciation permitted migration through northeastern Africa and, due to lowered sea levels, directly across the Red Sea to the Arabian Peninsula.

Nomadic human tribes likely entered parts of the Sahara Desert from the earliest days or our existence but extensive exploration and settlement of that harsh landscape would not occur until the Holocene, aided by the domestication of goats (10,000 YA), sheep (9000 YA), cattle (8000 YA) and dromedary camels (4000 YA). Even today, most human settlements lie in fringe regions of the Sahara and interior towns are limited to natural oases, the Nile Valley and volcanic highlands.

The Falklands & South Africa

When geologists first explored the Falkland Islands, 250 miles off the coast of southern Argentina, they found rock strata that did not correlate with those found on the mainland. Composed of igneous, metamorphic and volcanic rocks ranging from the Precambrian to the Jurassic, the two primary islands and their archipelago of numerous islets, were noted to possess a geological structure very similar to that found in South Africa. The solution to that mystery remained elusive until the theory of plate tectonics was proposed in the 1960s and has since been confirmed by field work.

As Pangea began to break up, some 200 million years ago, the Falkland microplate rifted from the southeast coast of South Africa and was pushed westward by rotation of the Antarctic Plate; since Africa, Antarctica and South America were still in close formation (as components of Gondwana), the Farallon microplate moved off with South America as the Atlantic Ocean opened during the Jurassic, some 150 million years ago. Indeed, dikes of Jurassic basalt are found on the islands and the Falkland Plateau, on which the islands rest, is Jurassic in age; like the Florida Platform, the Falkland Plateau swithed continents as the Atlantic rifted the Americas from Africa.

Today, the Falkland Islands, high points on the Falkland Plateau, sit near the edge of the Continental Shelf; though lying at a subpolar latitude, the islands benefit from the Brazil Current, which yields a more Temperate climate. Known for its fabulous diversity of marine mammals and sea birds (including five species of penguin), the Falklands are devoid of native amphibians, reptiles and terrestrial mammals. The Falkland wolf, now extinct, once roamed the islands, having likely wandered in from the mainland when sea levels fell during the Pleistocene.

Chiseling the African Plate

During the Permian Period, some 250 million years ago (MYA), future Africa was encased within the combined land mass of Pangea. Then, about 200 MYA, the Tethys Sea began to open, splitting Pangea from east to west and separating the northern continents (Laurasia) from the southern land masses (Gondwana); future Africa was part of the latter.

About 160 MYA, Madagascar split from southeast Africa and, 10 million years later, the Atlantic began to open. The combined mass of Africa and South America rifted from Antarctica about 140 MYA and the final separation of Africa and South America occured 100 MYA as the Atlantic Rift spread southward. As the Indian Ocean widened, some 50 MYA, the Tethys Sea began to close and Africa drifted northward to collide with the Eurasian Plate, crumpling up the Alps; the Mediterranean Sea is a remnant of the Tethys. Finally, the East African Rift began to form about 40 MYA; as the Red Sea opened, the Arabian Plate split from Africa and, today, continues to move to the northeast, colliding with southeast Asia. A string of lakes and volcanic summits through East Africa delineates the course of the Rift and marks the future edge of the Continent; as the rift continues to spread, the sea will invade its channel and a new land mass will split from the east side of the African Plate.

All of our planet's land masses have been molded in this way as seas open and close, causing the continental plates to merge or rift apart. The current map of our globe is but a snapshot in the 4.6 billion year history of Earth's evolution, a process that continues today.

Madagascar and its Primates

As Pangea continued to break apart, Madagascar split from Africa, some 160 million years ago. Drifting to the south, it merged with the remnants of Gondwanaland, the combined mass of Antarctica, India and Australia. There, its African flora and fauna mingled with the plants and animals of that tropical land mass. About 95 million years ago, the India-Madagascar segment broke from Antarctica-Australia, moving to the northeast; within another 15 million years, Madagascar began to rift from India, presumably triggered by an underlying hotspot that also produced the massive Deccan Traps basalt flow at the end of the Mesozoic. By 70 million years ago, Madagascar was moving into prolonged isolation and now rests 350 miles off the southeast coast of Africa.

While the earliest mammals arose during the Triassic, more than 200 million years ago, primates first appeared late in the Cretaceous, after Madagascar had become an isolated land mass. About 60 million years ago, these ancestral primates split into the prosimian line (which led to lemurs, lorises, galagos and pottos) and the anthrapoid line (leading to monkeys, apes and hominids). Spreading across the globe these two groups shared similar habitats and, over time, the anthrapoids were more successful, pushing the prosimians toward extinction.

According to current scientific theory, ancestral lemurs reached Madagascar on rafts of vegetation, torn from the African coast by seasonal storms. There, free from anthrapoid competition, they have flourished and, today, are represented by more than 100 species and subspecies. A second primate, humans, reached Madagascar by boat, colonizing the Earth's fourth largest island about 2000 years ago. Unfortunately, the Malagasy and their descendents have since destroyed much of the natural habitat; lemurs and other Madagascar animals, 80% of which are endemic to the island, are increasingly threatened by deforestation and other human activity.