Latest news with #Landsat7
Newsweek
06-07-2025
- Science
- Newsweek
Satellite Images Show How Much Lake Mead Has Shrunk in 25 Years
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Satellite images illustrate how water levels in Lake Mead have fallen in the past 25 years. Why It Matters Lake Mead supplies vital water to millions in Nevada, Arizona, California, and parts of Mexico. However, declining water levels could jeopardize city water systems, farm irrigation, and hydroelectric power output. Lake Mead is the largest reservoir in the U.S., capable of storing approximately 29 million acre-feet of water. It is closely followed Lake Powell, with a capacity of around 25 million acre-feet. Recent forecasts lowered runoff into Lake Powell to just 55 percent of average, down from an earlier estimate of 67 percent, due to an underwhelming winter snowpack. Lake Mead, which receives flows from Lake Powell, hit critically low levels during the summer of 2022, following years of drought. What To Know Satellite imagery captured by Landsat 7, a joint mission of the United States Geological Survey (USGS) and NASA, show a stark contrast in Lake Mead's water levels between July 1999 and May 2024, with the reservoir appearing noticeably smaller in the latter image. Landsat 7 image of the Las Vegas area and Lake Mead, acquired on July 4, 1999. Landsat 7 image of the Las Vegas area and Lake Mead, acquired on July 4, 1999. USGS Landsat 7 image of the Las Vegas area and Lake Mead, acquired on May 28, 2024. Landsat 7 image of the Las Vegas area and Lake Mead, acquired on May 28, 2024. USGS Images provided to Newsweek by Maxar Technologies further highlight Lake Mead's current levels compared to historical ones with the "bathtub ring" effect in display. Recent imagery provided by Maxar Technologies shows Lake Mead in 2025, with the "bathtub ring" visible along the coastline. Recent imagery provided by Maxar Technologies shows Lake Mead in 2025, with the "bathtub ring" visible along the coastline. Satellite image ©2025 Maxar Technologies Colin Williams, a mineral resources program coordinator with the USGS, told Newsweek previously that this ring around the lake is the result of calcium carbonate found in the Colorado River water. As the lake's water level fluctuates, these minerals cling to the surrounding rocks. When Lake Mead's water level drops, calcium carbonate is left behind on the rocks, forming the visible bathtub ring. "Lake Mead is full at 1,229 feet above sea level, so the bathtub ring disappears when the lake level is near that point," Williams said at the time. At the time of writing, Lake Mead's water levels were 1,054.85 feet mean sea level, 174.15 feet below its full pool of 1,229, according to Lakes Online, an online resource for lake and reservoir information. What People Are Saying Sharon Megdal, Director of the University of Arizona Water Resources Research Center, told Newsweek: "This time period has been dominated by lower annual natural river flows than those of the prior century. In addition, deliveries to water users in the Lower Basin, coupled with 1944 Treaty deliveries to Mexico have exceeded inflows, causing significant decline in the amount of water in storage since 2000. "Despite many interventions to prop up water levels in the reservoir, "Mother Nature's flows have not been generous," Megdal added. What Happens Next A recent study suggested that boosting wastewater recycling to 40 percent in the Colorado River Basin could conserve about 900,000 acre-feet of water annually—enough to supply nearly two million households. Meanwhile, the states that depend on the Colorado River have been in talks to establish new water-sharing agreements by 2026.
Yahoo
24-06-2025
- Science
- Yahoo
Final photo from iconic US satellite shows how Las Vegas has 'doubled' in size over the last 25 years
When you buy through links on our articles, Future and its syndication partners may earn a commission. QUICK FACTS Where is it? Las Vegas, Nevada [36.10457930, -115.1448612] What's in the photos? Aerial shots taken at the start and end of a satellite's operational lifespan Which satellite took the photos? Landsat 7 When were the photos taken? July 4, 1999 and May 28, 2024 The last image captured by the recently decommissioned Landsat 7 satellite shows the sprawling mass of Las Vegas flowering in the heart of the Mojave Desert. The final photo also mirrors one of the satellite's first-ever shots, highlighting how "Sin City" has rapidly expanded during the iconic spacecraft's 25-year lifespan. Landsat 7 is an Earth-observing satellite co-owned by NASA and the U.S. Geological Survey (USGS) that orbits our planet roughly every 99 minutes. It was launched on April 15, 1999, and has since taken more than 3.3 million images of Earth's surface, covering almost every square inch of the globe. On June 4, the satellite received its final transmission from operators, marking the official end of its mission after a year-long decommissioning process that took the spacecraft out of the path of other satellites before it ran out of fuel. Landsat 7 will now drift in space for around 55 years before eventually reentering and burning up in the atmosphere, according to a USGS statement. The satellite's final image was captured on May 28, 2024. It shows the Las Vegas metropolitan area, including towns such as Henderson, Paradise and Spring Valley, sprawled across the Nevada desert. The final image was taken from the same distance and angle as one of the satellite's first shots of the city, taken on July 4, 1999. Comparing the two side-by-side shows how much the city has expanded — nearly doubling in size. Related: See all the best images of Earth from space Between 2000 and 2023, the population of the Las Vegas metropolitan area went from 1.38 million to 2.33 million, which is an increase of around 69%, according to USGS. In 2025, an estimated 2.4 million live in the area. Lake Mead, an artificial reservoir of the Colorado River created by the Hoover Dam, can also be seen in both satellite images. The lake is noticeably smaller in the latest image, possibly due to increased water consumption in the region it serves or the effects of human-caused climate change. However, the lake's size naturally fluctuates, both seasonally and annually, making it hard to tell how it is being impacted by anthropogenic factors, according to NASA's Earth Observatory. Landsat 7 is the seventh satellite in the Landsat program, which has been continuously capturing images of Earth's surface since 1972. It was a serious upgrade from previous iterations and was particularly good at photographing urban areas, which was its primary focus. The spacecraft played a major role in the development of mapping services, including Google Maps, and also captured unique perspectives of some iconic moments in recent history, including the 9/11 terror attacks, Hurricane Katrina, and the Deepwater Horizon oil spill. The satellite was only designed to operate for five years, but it has far exceeded this target, despite suffering a significant instrument failure in 2003, which was later fixed. NASA previously reconsidered refueling the satellite in orbit to extend its lifespan, but this first-of-its-kind maneuver was never attempted. MORE EARTH FROM SPACE —Quadruple volcanoes on secret Soviet military base linked to climate-altering eruption 200 years ago —A mysterious 'black hole' in Pacific Ocean that sparked wild rumors online —The mysterious hill in Sudan that looks like 'landlocked lips' There are now only two operational Landsat satellites circling our planet: Landsat 8, which has been in orbit for more than 12 years; and Landsat 9, which launched in September 2021. The 10th Landsat satellite, named Landsat Next, was supposed to be launched by 2031. However, its funding is now uncertain thanks to the drastic cuts to NASA's budget proposed by the Trump administration, and mission experts are now "assessing alternate mission architectures," according to the Landsat Next homepage.
