Ghana, a nation rich in mineral resources, has a long history of gold mining. Gold comprises 90 percent of Ghana's mineral export. People have been mining for gold in Ghana for centuries. Long before European colonists set foot in the area in the 1400s, Ghanaians looked for gold with pickaxes, shovels, and pans.
They washed or “panned” for gold along river banks or dug holes on the surface to find deposits of gold dust and nuggets. A version of this small-scale mining persists-known today as artisanal mining-but new research shows it is having a growing and sometimes devastating effect on the environment.
Recent Gold Nugget Find Sparks Excitement and Concern
Recently, a video surfaced online showing men with a supposed massive gold nugget, igniting both excitement and concern among viewers. You can watch the footage here!
The post originated from Ghana. The finding is yet to be confirmed by authorities, but if it is what it appears to be, it’s without a doubt in the running for some kind of record. With this in mind, viewers have been questioning why the men ever allowed the footage to be posted online. Others were more interested in the worth of the supposed gold finding.
However, some viewers have expressed skepticism, with comments such as "Doesn't really look like gold" and "I did the math too it doesn't add up."
Read also: Hotel in Mauritius
To provide context, the largest gold nugget to date was discovered in Australia in 1869 and it weighed 72kg (156 pounds). If a nugget of its size was found today, experts estimate it would be worth around $2 million.
The Welcome Stranger Gold Nugget, found in Australia in 1869.
The "Welcome Stranger" Nugget
The "Welcome Stranger" is the biggest alluvial gold nugget that has ever been found, which had a calculated refined weight of 97.14 kilograms (214.16 lbs). *Note: There are differing reports on the actual size of the "Welcome Stranger" nugget.
Environmental issues related to Artisanal and Small-Scale Mining in Ghana by Pr. Frank Nyamé
The Environmental Impact of Artisanal Mining
Universities, and government agencies in Ghana recently used satellite data to estimate the extent of vegetation lost to artisanal mining in the southwestern portion of the country, where the majority of gold mining takes place.
“The accumulation of the small-scale mines across the landscape is startling. The deforestation impact is huge compared to industrial mines,” said Abigail Barenblitt, the main author of the study and data analyst in the biosphere sciences lab at NASA’s Goddard Space Flight Center.
Read also: Radio Gold's Frequency
The natural-color image shows a large-scale mine and several artisanal mines in the Central Region of Ghana. (Image: NASA Earth Observatory)
The differing impact of artisanal and industrial mines is related to the process of gold extraction, said study co-author Amanda Payton of East Carolina University. Large-scale industrial mines use heavy machinery to dig deep in a concentrated area. Because they typically do not have heavy-duty equipment, artisanal miners tend to dig many shallow holes across large swaths of land.
They extract and process gold at the site and then move onto the next area. They usually do not refill holes after extractions. And they often use mercury to remove gold from sediments, which can lead to serious health problems and long-term water and soil contamination.
“Artisanal mining has a quicker turnaround time on the landscape, with operations excavating a shallower area and then moving on to another section of the river. Some of the artisanal mines stretch for great distances along rivers,” said Payton.
Barenblitt, Payton, and colleagues worked with the Ghana Space Science and Technology Institute and Ghana Statistical Service to determine the total footprint of vegetation loss to artisanal gold mining. They analyzed decades of Landsat data, creating a machine-learning algorithm to classify any vegetation loss in one of four categories: mining, urban development, water, and other (agriculture, bare soil, etc.).
Read also: Culture and Gold in Ethiopia
The team found more than 160,000 hectares (400,000 acres) of vegetation were lost from 2005-2019. About 28 percent was lost to both industrial and artisanal gold mining, while 29 percent was lost to urban development. About 17 percent was converted to water, mainly due to the formation of a lagoon complex.
The team further classified mining as large-scale industrial or small-scale artisanal by looking at elevation data and the texture of the landscape. Industrial mines have larger elevation changes since they dig deeper into the surface. Highly textured landscapes tend to indicate artisanal mining due to the small holes compared to wider, smoother industrial areas.
The team also calculated artisanal mining activity by year to pinpoint its rise in popularity over the past decade. The map above shows new mining activity over a subset of the study period from 2007 to 2017 near Kumasi, Ghana. (The researchers chose 2007 to 2017 to focus on years with sufficient cloud-free imagery to identify annual changes.) Darker orange and red represent more recent activity.
New mining activity near Kumasi, Ghana, from 2007 to 2017. (Image: NASA Earth Observatory)
At least 700 hectares (1,700 acres) of loss occurred in protected zones.
“There has definitely been an expansion of small-scale mining by more people over time because of the price of gold,” said Lola Fatoyinbo, a forest ecologist at NASA’s Goddard Space Flight Center and a contributor to the study. “The high gold prices probably made artisanal mining worth the labor.”
The team calculated a correlation between gold prices and annual mining conversion after a two-year lag.
The team’s next step is to automate their image analysis process so new mining can be detected quickly by African and international organizations addressing the issue. This research is part of larger efforts across NASA to detect unregulated gold mining in Ghana. Agency for International Development (USAID).
| Category | Percentage of Vegetation Loss (2005-2019) |
|---|---|
| Industrial and Artisanal Gold Mining | 28% |
| Urban Development | 29% |
| Conversion to Water | 17% |
| Other (Agriculture, Bare Soil, etc.) | Remaining Percentage |
Popular articles:
tags: #Ghana
