America’s rivers are changing color — and people are behind many of the shifts, a new study said.

One-third of the tens of thousands of mile-long (two kilometer-long) river segments in the United States have noticeably shifted color in satellite images since 1984. That includes 11,629 miles (18,715 kilometers) that became greener, or went toward the violet end of the color spectrum, according to a study in this week’s journal Geographical Research Letters. Some river segments became more red.

Only about 5% of U.S. river mileage is considered blue — a color often equated with pristine waters by the general public. About two-thirds of American rivers are yellow, which signals they have lots of soil in them.

But 28% of the rivers are green, which often indicates they are choked with algae. And researchers found 2% of U.S. rivers over the years shifted from dominantly yellow to distinctly green.

“If things are becoming more green, that’s a problem,” said study lead author John Gardner, a University of Pittsburgh geology and environmental sciences professor. Although some green tint to rivers can be normal, Gardener said, it often means large algae blooms that cause oxygen loss and can produce toxins.

The chief causes of color changes are farm fertilizer run-off, dams, efforts to fight soil erosion and man-made climate change, which increases water temperature and rain-related run-off, the study authors said.

“We change our rivers a lot. A lot of that has to do with human activity,” said study co-author Tamlin Pavelsky, a professor of global hydrology at the University of North Carolina.

For example, Pavelsky said, the green at times in the Ohio River indicates a bad algae problem from farm runoff while rivers that are getting less yellow demonstrate the success of regulations to prevent soil erosion.

The study looked at more than 230,000 NASA satellite images over 35 years, focusing on rivers and reservoirs. The study found much of the shift to greener rivers happened in the North and West, while the yellowing occurred more in the East and around the Mississippi River. It also found some rivers change colors naturally with the seasons.

Outside experts praised the study, saying while hard-to-understand measurements have shown problems with American rivers, this illustrates the situation simply.

The study “is super cool and a bit mind-blowing (yet intuitive),” Martin Doyle, head of water programs at Duke University, wrote in an email. “It shows how most every aspect of our planet is being affected by humans, now including the basic color of our water. That’s pretty profound if you think about it.”

“It’s also important because it opens up the idea and potential of using river color as early-stage indicator, or warning of environmental change,” wrote Doyle, who wasn’t part of the study.

BEIJING — Chinese automaker Geely says it will form an electric car venture with tech giant Baidu, adding to a flurry of corporate tie-ups in the industry to share soaring technology development costs.

Geely Holding Group, which also has separate electric car brands, said Monday the venture with Baidu.com Inc. would focus on intelligent and connected vehicles. It gave no details of investment or when products might be released.

Global and Chinese automakers have launched partnerships to share the multibillion-dollar costs of developing electric vehicles for China under government pressure to meet sales quotas.

China is the world’s biggest market for the technology, accounting for about half of global sales. The ruling Communist Party spent billions of dollars on subsidies in an attempt to take an early lead in the industry. It is shifting the burden to manufacturers by requiring them to earn credits from selling electric vehicles or face penalties that have yet to be announced.

Privately held Geely, best known abroad as the owner of Sweden’s Volvo Cars, is one of China’s biggest independent automakers. Its brands include Geely, Lynk & Co., Geometry and Polestar, all of which sell electric vehicles. Geely is the biggest shareholder in Malaysia’s Proton and Britain’s Lotus.

Baidu operates China’s most popular internet search engine. It is regarded as one of the world’s leading developers of automated driving technology.

MEXICO CITY — Farmers digging in a citrus grove near Mexico’s Gulf coast have found a striking, six-foot-tall statue of a female figure who may represent an elite woman rather than a goddess, or some mixture of the two, experts said Friday.

The National Institute of Anthropology and History said it was the first such statue found in a region known as the Huasteca.

The carved woman has an elaborate hairpiece and marks of status, and may date to around 1450 to 1521, the institute said. While the site where it was found is nearer to the pre-Hispanic ruin site of El Tajín, the statue shows some influences of the Aztecs.

Farmers digging in the grove found it on New Year’s Day and quickly reported it to authorities. The area where it was found was not previously known to be an archeological site, and the stone statue may have been moved from some unknown original site.

Just who the open-mouthed, wide-eyed statue depicts remains something of a mystery.

Institute archaeologist María Eugenia Maldonado Vite wrote that “this could be a ruler, based on her posture and attire, more than a goddess.”

Maldonado added it could be “a late fusion between the Teem goddesses and women of high political or social status in the Huasteca.” Those goddesses were part of a fertility cult.

Susan Gillespie, an anthropology professor at the University of Florida, said there “there are quite a few pre-Hispanic depictions of elite women and female rulers elsewhere, best known among the Classic Maya but also in Classic Zapotec bas-reliefs and Postclassic Mixtec codices.”

“Colonial era Aztec documents mentioned women ‘rulers’ or at least holders of the crown to pass on to their successors … so that is not a surprise,” Gillespie added. “Women were highly valued in the pre-Hispanic era, drastically losing their status only after the conquest.”

However, she noted that “if there is only one such find, it’s hard to say whether it is significant, or even correctly identified. Archaeology works best with repeated occurrences, to show a pattern.”

In 1994 in the Mayan ruin site of Palenque, archaeologists found the tomb of a woman dubbed The Red Queen because of the red pigment covering her tomb. But it has never been firmly established that the woman, whose tomb dates from between 600 and 700 A.D., was a ruler of Palenque.

DETROIT — General Motors is changing its corporate logo and launching an electric vehicle marketing campaign to reshape its image as clean vehicle company, rather than a builder of gas-powered pickups and SUVs.

The 112-year-old Detroit automaker has promised to roll out 30 new battery-powered vehicles globally by the end of 2025 and said Friday that the new campaign will highlight its progressive vision for the future.

GM said the industry has reached a history-changing inflection point for mass adoption of electric vehicles.

The campaign comes as stock market investors are enthralled with companies that make electric vehicles. Shares of global EV leader Tesla Inc. have skyrocketed more than 800% in the past year, and the company’s market value has passed $800 billion. GM’s shares are only up slightly in the past year and its value is around $61 billion.

Shares of GM were down 1.6% to $42.61 in Friday afternoon trading.

GM is scrapping its old square blue logo and replacing it with a lower case gm surrounded by rounded corners. The company says it’s the biggest change to its logo since 1964. The ‘m’ in the logo is underlined to look more like an electrical plug.

“We felt it was just such a transformative moment that this is the time that we would change again,” said Deborah Wahl, GM global chief marketing officer. “Our message here is that we believe there should be an EV for everyone.”

GM is hoping the “Everybody In” campaign prepares buyers for a new era of vehicle propulsion.

Wahl said the marketing campaign will be “very significant,” but she wouldn’t say how much money would be spent or where it will show up. “You will see it in many places throughout the year,” she said Friday. She said the campaign will start in the United States but eventually will become global. It will not be in brand ads for vehicles, Wahl said.

Late last year, GM said it was nearing a battery chemistry breakthrough that will make electric vehicles as affordable as those with internal combustion engines in less than five years. Some will be able to go up to 450 miles per charge and from zero to 60 mph (97 kilometers per hour) in as quickly as three seconds.

The company has promised to spend $27 billion on battery vehicles through 2025.

The new logo will go wherever GM now has a logo, including websites and buildings, Wahl said.

The company stopped putting the logo on car bodies about a decade ago as it started to emphasize individual brands. But GM says the new logo eventually will replace the old one on window glass and some other parts.

The marketing campaign will feature celebrities including Malcom Gladwell, author of “The Tipping Point.”

A campaign of “Everyone In” conflicts a bit with GM’s announced plans for electric vehicles such as a GMC Hummer pickup and Cadillac Lyriq SUV, both higher-priced vehicles. But Wahl said lower priced vehicles are among the 30 new electric vehicles that are coming.

GM officials have said previously that they will have a small electric SUV that will cost less than $30,000 within five years.

The campaign will run ahead of current electric vehicle sales trends in the U.S. Last year automakers sold just over 260,000 fully electric vehicles. Although sales were up nearly 10% over 2019, electric vehicles still were less than 2% of new vehicle sales.