Africa on EARTH Magazine

Trio of studies track stone tool technology in Kenya

Tue, 05 Jun 2018 17:02:59 -0400

About 300,000 years ago, East Africa was a hotbed of human evolution and innovation. Sweeping ecological changes contributed to the emergence of modern humans, and spurred the first long-distance trade routes and novel toolmaking technologies. Three new studies published in Science shine a spotlight on Kenya’s Olorgesailie Basin, where the clunkier Acheulean tool technology gave way to the smaller, sleeker Middle Stone Age tool technology famously associated with Homo sapiens.

Battery recycling underlies elevated lead in African soils

Tue, 10 Apr 2018 11:22:11 -0400

Lead-acid batteries — used to power motor vehicles and cellphone towers, and for power storage at wind and solar farms — are one of the most recyclable products, but they are also highly toxic. Credit: baselactionnetwork, CC BY-ND 2.0.

Of all the recycling industries in the world, lead-acid battery recycling is one of the most profitable — and one of the most toxic. In the U.S., regulations on the industry have dramatically reduced lead exposure and pollution at battery recycling plants. But in Africa, where the industry is growing and largely unregulated, lead levels are skyrocketing. A new study in Environmental Research looking at environmental lead levels in seven African countries is shining a spotlight on the ongoing public health crisis.

Glass shards reveal a fiery history in Ethiopia

Thu, 14 Sep 2017 11:51:18 -0400

Scientists drilled below Lake Ashenge, on the western border of the Afar Triangle, for evidence of past eruptions. Credit: Catherine Martin-Jones.

Chains of volcanoes and a lava lake pepper the landscape of the Afar Triangle in northeastern Ethiopia, where eruptions and earthquakes are byproducts of the rifting that is literally ripping Africa apart, but recent eruptions have been docile. Now, scientists studying ash deposits from the last 40,000 years are showing that dangerous, explosive eruptions present an ongoing hazard, striking the region every 1,000 years on average.

Getting there and getting around Kalahari

Mon, 22 May 2017 11:43:32 -0400

It's best not to drive in Botswana after dark to avoid collisions with wildlife. Credit: Lon Abbott and Terri Cook.

“There are three gateway cities to the Kalahari, all of which are at least a day’s drive from the Okavango Delta. Although it’s the farthest (about 12 hours away), the O.R. Tambo International Airport (JNB) in Johannesburg, South Africa, is the region’s largest and often has the best airfares and car-rental rates. Two closer alternatives, each about an eight-hour drive away, are Botswana’s Sir Seretse Khama International Airport (GBE) in Gaborone and Namibia’s Hosea Kutako International Airport (WDH) in Windhoek. Maun (MUB) is Botswana’s primary tourist hub and the delta’s main service town. Most accommodations there provide a free minibus transfer from the airport.

Travels in Geology: Tracking African animals and deranged drainages across the Kalahari

Fri, 19 May 2017 12:03:03 -0400

The local name for Victoria Falls translates as "The Smoke That Thunders." Credit: Lon Abbott and Terri Cook.

After landing in Windhoek, Namibia, on the western edge of the Kalahari Desert, our family embarked on an African adventure with two exhilarating objectives: to see iconic African animals in the Okavango Delta, a major river delta in the middle of the dry Kalahari, and to view the thundering Victoria Falls, a day’s drive from the delta on the desert’s northeastern side. Most tourists consider these two magnificent UNESCO World Heritage sites to be wholly unrelated. But to a geologist, they are inextricably linked via major hydrologic changes that have swept across the region in response to both subtle tectonic movements and major Pleistocene climate fluctuations.

Early humans dealt with Ethiopian supervolcanoes

Wed, 08 Feb 2017 14:05:12 -0500

Modern geochronological techniques were used to calculate the age of volcanic deposits and build an eruptive history for the volcanoes of the Ethiopian Rift. Credit: William Hutchison.

About 200,000 years ago, modern humans evolved in East Africa, including in what’s now Ethiopia. They — like earlier hominins who had preceded them — likely encountered occasional explosive eruptions spewing ash and lava into the air and onto the landscape, according to a new study in Nature Communications.

Teaching geology to biologists: An essay on an interdisciplinary field trip in Africa

Mon, 25 Jul 2016 14:21:50 -0400

Jill Peterson, an Adams State student on the trip, painted this representation of the field trip. Credit: Jill Peterson.

We stop next to a wide, dry, creek bed on the floor of a steep canyon near Tarangire National Park in northern Tanzania. Elephants spray water on themselves and their companions. In the tall baobab trees on the far side of the valley, monkeys jump from limb to limb and tree to tree, over the heads of impalas that don’t seem to care. I am standing in the back of one of our open-top Land Rovers and, like the monkeys, I’m waving my arms this way and that as I discuss the geologic strata in the canyon walls. Like the impalas, the khaki-clad college students in the Land Rovers don’t seem to notice.

Double trouble: Volcanic eruption leads to strong earthquake eight months later

Fri, 20 May 2016 13:54:43 -0400

The deadly January 2002 eruption of the Nyiragongo Volcano in the Democratic Republic of the Congo also triggered a damaging earthquake in October 2002 near Lake Kivu. Credit: Christelle Wauthier/Penn State.

In January 2002, Nyiragongo Volcano erupted in the Democratic Republic of the Congo, killing more than 100 people. Eight months later and 19 kilometers to the south, a magnitude-6.2 earthquake shook the Lake Kivu region, partially destroying the town of Kalehe. Now, scientists have determined that the two events were linked, and their results highlight a newly observed trigger for strong earthquakes near active volcanoes.

Irrigation drives rain away in East Africa

Thu, 07 Jan 2016 11:31:33 -0500

Croplands in the Gezira Scheme in Sudan, near the confluence of the Blue Nile and White Nile, are watered by a vast network of irrigation canals. Credit: NASA.

Researchers have found that large-scale agricultural irrigation, intended to supplement precipitation, may actually drive rainfall away, potentially exacerbating conditions in some areas while improving them in nonirrigated lands.

Widespread malaria risk from African dams

Thu, 31 Dec 2015 13:46:12 -0500

Map of existing and planned large dams considered in a new study that analyzed rates of malaria infection near the dams in areas where malaria transmission is stable (perennial) versus unstable (seasonal). Credit: Kibret et al., Malaria Journal, 2015.

Large dams cause more than 1 million cases of malaria annually in sub-Saharan Africa, according to the authors of a new study published in Malaria Journal.

Finding and tracking conflict minerals in the heart of darkness

Tue, 06 Oct 2015 10:24:06 -0400

Millions of Democratic Republic of the Congo (DRC) residents have been displaced by warring militias, funded by the minerals trade. Clockwise from top left: Refugees flee a refugee camp as gunfire erupts nearby. Children mine at the Kaji gold mine in South Kivu in the DRC. As Western consumers have become more aware of conflict minerals, they are stepping up pressure on electronics producers. Credit: clockwise from top left: Julien Harneis, CC BY-SA 2.0; Sasha Lezhnev, Enough Project, CC BY-NC-ND 2.0; Jonathan Hutson, Enough Project, CC BY-NC-ND 2.0.

fugee camp in Kitchanga, North Kivu. Credit: Sasha Lezhnev, Enough Project, CC BY-NC-ND 2.0.

Deep within the eastern Democratic Republic of the Congo (DRC), in a mountainous jungle that is home to volcanoes and silverback gorillas, lies a mining region like no other. The ore pulled from the ground here helped the U.S. build the atomic bomb and supplied the Western world’s technology revolution of the 1990s and 2000s, which brought consumers devices like the mobile phone and laptop computer.

Ancient floods degassed Lake Kivu

Wed, 02 Sep 2015 11:27:55 -0400

A turbid sediment plume in Lake Kivu in East Africa following a rainfall event. The discovery of ancient megaturbidites in the lake that had been instigated by floods revealed a new trigger for degassing the "killer lake." Credit: Christopher Scholz.

The deep, cold waters of Lake Kivu — a stratified volcanic lake in the East African Rift Valley on the border of Rwanda and the Democratic Republic of the Congo — hold 300 cubic kilometers of carbon dioxide gas and 60 cubic kilometers of methane, which seep from magmatic sources below the lake. An overturning of the thermally stratified waters could release those deadly gases onto a population of nearly 2 million.

Earliest stone tools pre-date Homo

Mon, 24 Aug 2015 10:26:18 -0400

Sonia Harmand examines a primitive stone tool found in Kenya. Credit: MPK-West Turkana Archaeological Project.

Tool making is thought to be one of the defining characteristics of the transition from apes to early man. Now, the discovery of a set of stone tools dating to 3.3 million years ago is pushing back this critical stage of early human development by more than half a million years, and, according to one researcher involved, disproving “the long-standing assumption that Homo habilis was the first tool maker.”

One whale's incredible journey details East Africa's uplift

Tue, 16 Jun 2015 11:55:16 -0400

About 17 million years ago, a 7-meter-long beaked whale took a wrong turn off Africa’s east coast and swam hundreds of kilometers up the Anza River before stranding. In 1964, the fossilized remains of the wayward whale were discovered at high elevation in West Turkana, Kenya, and then transported to the U.S., where they were subsequently lost in storage for more than 30 years before being rediscovered at Harvard in 2011. The whale’s incredible journey is now providing crucial clues about the timing of uplift in East Africa.

Monkeys in the New World earlier than thought

Mon, 01 Jun 2015 09:36:47 -0400

A strong resemblance between a newly discovered Peruvian primate and African species supports the theory of dispersal from Africa to South America. Credit: Ron Blakey.

Monkeys originated in Africa, but how and when they first appeared in Central and South America has long been something of a mystery. Now, a new set of fossilized teeth places monkeys in South America about 10 million years earlier than previously thought.

The new anthropology: From bones and stones to biology and behavior

Tue, 05 May 2015 09:25:52 -0400

Grasslands in Tanzania's Serengeti National Park in East Africa may be similar to some of the habitats in which early humans evolved. Credit: ©Noel Feans, CC BY-2.0.

Paleoanthropology has traditionally been a dusty science, with new discoveries usually involving bones, teeth and stone tools painstakingly picked from the dirt. But in recent years, the field has embraced a more integrated approach to understanding our ancestors, studying them not just in terms of their skeletons and artifacts, but also their biology and behavior as formerly living, breathing organisms.

Out of Africa, time and again

Tue, 02 Sep 2014 13:36:35 -0400

A study of genetic data and the shapes of skull bones among indigenous populations from Asia, Australia and Melanesia suggests modern humans left Africa in multiple waves separated by tens of thousands of years. Credit: ©Gossipguy, CC BY-SA 3.0.

There is widespread agreement among scientists based on fossil and geochemical evidence that modern humans evolved in Africa between 200,000 and 100,000 years ago before spreading around the world. But the timing and route of this dispersal, and whether it occurred as a single exodus or in multiple pulses, remain contested. Now, a new study throws its weight behind a multiple-dispersal hypothesis, suggesting a first group of modern humans left Africa as early as 130,000 years ago, followed by a second about 80,000 years later.

Benchmarks: August 15, 1984 & August 21, 1986: African killer lakes erupt

Mon, 11 Aug 2014 15:23:07 -0400

In August 1986, a carbon dioxide eruption from Lake Nyos in Cameroon killed more than 1,700 people. This photo was taken in early September 1986 by U.S. Geological Survey scientists studying the disaster. Credit: USGS.

Only three lakes in the world are known to explosively release dissolved gases from their bottom waters. All three are in Africa; two have erupted with deadly consequences.

Mapping how malaria risk changes as new dams go up

Thu, 17 Apr 2014 15:07:58 -0400

Malaria is considered a leading public health problem in Ethiopia, with almost 70 percent of the country’s total population of more than 90 million people at risk from the deadly disease. Now, researchers are studying how hydroelectric dams affect malaria prevalence by combining computer simulations with field data from the Ethiopian countryside. The hope is that the new research could provide fresh insight for malarial management programs.

Modern humans arrived in South Asia 25,000 years later than previously thought?

Wed, 12 Jun 2013 12:59:14 -0400

Stone tools and artifacts dated to 40,000 to 50,000 years ago from South Asia (shown) resemble slightly older finds in South and East Africa. Illustrations by Dora Kemp, McDonald Institute for Archaeological Research, Cambridge University

Figuring out when modern humans left Africa and migrated throughout the world is a complicated task. For example, some evidence suggests modern humans may have migrated out of Africa and into Asia as early as 120,000 years ago. Further evidence puts modern humans in India and other parts of South Asia prior to the super-eruption of Mount Toba in Sumatra, which took place 74,000 years ago. However, new research suggests that modern humans may not have reached South Asia until well after the Toba eruption.

Oceanic records paint a more complex picture of human evolution

Tue, 28 May 2013 17:17:06 -0400

It has long been hypothesized that human ancestors evolved the ability to walk upright — a feature that appeared about 6 million years ago — in response to African landscapes changing from forests to grasslands. Now, a group of scientists has assembled the most continuous timeline of landscape evolution and grassland development over the last 12 million years near the African Rift Valley in northeastern Africa — and the timeline contradicts conventional hypotheses.

Paleo Patrol: Out of Africa and into Arabia?

Thu, 05 Jan 2012 06:41:58 -0500

How and when did modern humans leave Africa and colonize the rest of the world? Many archaeologists would probably tell you that about 60,000 years ago, Homo sapiens walked up through Egypt, crossed the Sinai Peninsula into the Levant region of the Middle East and then continued on to Eurasia.