Natural Disaster - Blog Posts

10 Ground-breaking Earth Satellite Images from 2018

In 2018, our satellites captured beautiful imagery from throughout the solar system and beyond. However, some of our favorite visualizations are of this very planet. While this list is by no means exhaustive, it does capture some Earth satellite images from this year that are both visually striking as well as scientifically informative. This list also represents a broad variety of Earth’s features, as well as satellite instrumentation. Take a journey with our eyes in the sky!

10. Hurricane Florence

Before making landfall, Hurricane Florence churned in the Atlantic for a full two weeks — making it among the longest-lived cyclones of the 2018 season. When it finally did hit land on Sep. 14, the storm devastated the southeastern U.S. coast with intense winds, torrential rains and severe flooding.

This natural-color image was acquired by MODIS on the Terra Satellite on Sep. 12, 2018. 

Images like this, as well as other satellite information, were used to anticipate the impact of the storm. Our Disasters Program created flood proxy maps that were shared with the Federal Emergency Management Agency (FEMA) and the National Guard to estimate how many and which communities would be most affected by the storm, in order to help prepare recovery efforts ahead of time.

9. Australia’s Lake Eyre Basin

The Lake Eyre Basin covers one-sixth of Australia and is one of the world’s largest internally draining river systems. However, the rivers supported by this system are ephemeral, meaning that they only run for short periods of time following unpredictable rain — the rest of the time, the Basin is a dry, arid desert.

However, when the heavy rain comes, the basin erupts in an explosion of green. In this false-color image captured by the Operational Land Imager (OLI) on Landsat 8 on Apr. 25, 2018, you can see how the vegetation completely envelops the spaces where the water has receded. (Flood water is indicated by light blue, and vegetation is indicated by light green.)

Satellites are an excellent tool for tracking greening events that are followed by flooding. These events offer opportunities for predictive tools as well as recreation.

8. Alaska’s Chukchi Sea 

A Monet painting comes to life as the Chukchi Sea swirls with microscopic marine algae.

This image was captured off the Alaskan coast by OLI on Landsat 8 on Jun. 18, 2018. After the Arctic sea ice breaks up each spring, the nutrient-rich Bering Sea water mixes with the nutrient-poor Alaskan coastal water. Each type of water brings with it a different type of phytoplankton and the surface waters have just enough light for the algae to populate and flourish. The result is these mesmerizing patterns of turquoise and green.

This image represents one piece of much larger, incredibly complex ecosystem. While one would not normally associate the breaking up of sea ice with phytoplankton blooms, it is an intricate process of the phytoplankton life cycle. The size of the blooms have varied greatly from year to year, and experts are unsure why. Images like these can help scientists track the development of these blooms and link it to other environmental changes.

7. Hawaii’s Kilauea 

Sometimes fresh lava is best viewed in infrared.

This false-color image of Kilauea, captured by OLI on Landsat 8 on May 23, 2018, shows the infrared signal emitted by lava flowing toward the sea. The purple areas surrounding the glowing lava are clouds lit from below, indicating that this image was taken through a break in the clouds.

The Puʻu ʻŌʻō Kupaianaha eruption has been continuously spewing red-hot lava since 1983, making it the longest eruption at Kilauea in recorded history. However, new fissures opened up this year that forced many to evacuate the area. Hawaii’s largest lake evaporated in hours and hundreds of homes were destroyed in Vacationland and Kapoho. 

Imagery, seismometers and ground-based instruments were used to track the underground movement of magma. Infrared imagery can be incredibly helpful in disasters like this when you to view data that cannot be observed with the naked eye. 

6. California’s Woolsey Burn Scar

Nothing quite encapsulates the destruction of a wildfire like a photo from outer space.

This image of the Woolsey Fire aftermath in Southern California was captured on Nov. 18, 2018 by the Advanced Spaceborned Thermal Emission and Reflection Radiometer (ASTER) on the Terra satellite. This false-color infrared image has been enhanced to clearly show the burned vegetation (indicated by brown) and the vegetation that survived unscathed (indicated by green).

The Woolsey Fire clearly left its mark, with almost 152 square miles (394 square km) and 88% of the Santa Monica Mountains National Recreation Area badly burned. Images like this one can assist fire managers in the area plan for recovery. 

5. Bangladesh’s Padma River

As the years go by, the Padma River grows and shrinks, twists and turns. It never has a fixed shape, and as a result, thousands of people must regularly adapt to the constant changes in the river’s 75-mile (130-km) shoreline.

This image captured on Jan. 20, 2018 by OLI on Landsat 8 depicts one of the major rivers of Bangladesh. For thirty years, scientists have been tracking the erosion of the river with satellite imagery. Combinations of shortwave infrared, near infrared, and visible light are used to detect differences year-to-year in width, depth, and shape of the river. Sometimes the river splits off, but then rejoins again later. These patterns are created by the river carrying and depositing sediment, shaping the curves of the path of water.

Monitoring the Padma River is going to become especially important as a new bridge development project advances in the Char Janajat area. Although the bridge will most certainly help shorten travel times for citizens, nobody is quite sure how the river erosion might affect the construction and vice versa. 

4. Alaska’s Yakutat Glacier 

It’s hard to believe that Harlequin Lake was once all dry land — but it only started to form once Yakutat Glacier started melting. The lake appeared at the beginning of the twentieth century, and has been growing rapidly ever since.

In this hauntingly beautiful image, captured on Sep. 21 2018 by OLI on Landsat 8, the effect of climate change is apparent — especially when compared to earlier images of the region.

Unless the climate warming starts to reverse very soon — which scientists consider very unlikely — Yakutat could be gone as soon as 2070.

3. South Africa’s Theewaterskloof

Cape Town is a seaside city planted on the tip of South Africa. It’s a city known for its beaches and biodiversity — it also almost became known as the first major city to officially run out of water.

This image of Cape Town’s largest reservoir — Theewaterskloof — was acquired on Jul. 9th, 2018 by OLI on Landsat 8. By the time this photo was taken, the city’s main reservoirs stood at 55%. This was a huge increase from where it stood just six months earlier: just 13%.

The severe water shortage in the region started in 2015, only to become more threatening after three successive and unusually dry years. The entire city was preparing for Day Zero — the day the tap water would be shut off.  

Despite forecasts that Day Zero would arrive in April, a combination of heavier rains and local conservation efforts restored the majority of the reservoir. 

2. Aerosol Earth

Aerosols are all around us. From the smoke from a fire, to the dust in the wind to the salt in sea spray — these solid particles and liquid droplets are always swirling in our atmosphere, oftentimes unseen.

The Goddard Earth Observing System Forward Processing (GEOS FP) model uses mathematical equations to model what is happening in our atmosphere. The inputs for its equations — temperature, moisture, wind, etc. — come from our satellites and ground sensors.

This visualization was compiled on Aug. 24, 2018 — obviously a busy day for aerosols in our atmosphere. Swirls of sea salt (indicated by blue) reveal typhoons Soulik and Cimaron heading straight towards South Korea and Japan. A haze of black carbon (indicated by red) suffuse from agricultural burning in Africa and large wildfires in North America. And clouds of dust (indicated by purple) float off the Sahara desert.

1. Camp Fire

With nearly a hundred fatalities, hundreds of thousands of acres burned and billions of dollars of damage, the world watched in horror as Camp Fire grew to become the most destructive California wildfire in recorded history.

This image was captured on Nov. 8, 2018 by OLI on Landsat 8 on the same day Camp Fire ignited. It consolidates both visible light and shortwave-infrared light in order to highlight the active fire. Strong winds and dry conditions literally fanned the flames and spread this wildfire like a rash. 

This image has not only become the iconic portrait for Camp Fire, it is also sobering representation of how quickly a fire can grow out of control in a short amount of time. Even from space, you can almost smell the massive plumes of smoke and feel the heat of the fires.

Whether you realize it or not, our Earth satellite missions are collecting data everyday in order to monitor environmental changes and prepare for natural disasters.  If your interest is piqued by this list, head over to the Earth Observatory. The Earth Observatory updates daily with fresh, new content — brought to you by none other than our eyes in the sky. 

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The Darkness that Followed Hurricane Michael

Earlier this month, the southeastern United States was struck by Hurricane Michael. After the category 4 storm made landfall on Oct. 10, 2018, Hurricane Michael proceeded to knock out power for at least 2.5 million customers across Florida, Georgia, North Carolina, and Virginia. 

In this data visualization, you can clearly see where the lights were taken out in Panama City, Florida. A team of our scientists from Goddard Space Flight Center processed and corrected the raw data to filter out stray light from the Moon, fires, airglow, and any other sources that are not electric lights. They also removed atmosphere interference from dust, haze, and clouds. 

In the visualization above, you can see a natural view of the night lights—and a step of the filtering process in an effort to clean up some of the cloud cover. The line through the middle is the path Hurricane Michael took. 

Although the damage was severe, tens of thousands of electric power industry workers from all over the country—and even Canada—worked together to restore power to the affected areas. Most of the power was restored by Oct. 15, but some people still need to wait a little longer for the power grids to be rebuilt. Read more here. 

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5 Things: How Hurricanes Have Changed Puerto Rico’s Forests

In September 2017, Hurricanes Irma and Maria hit Puerto Rico, knocking out critical infrastructure and ransacking the island’s forests. In April and May 2018, a team of our scientists took to the air to take three-dimensional images of Puerto Rico’s forests using Goddard’s Lidar, Hyperspectral, and Thermal Imager (G-LIHT), which uses light in the form of a pulsed laser. By comparing images of the same forests taken by the team before and after the storm, scientists will be able to use those data to study how hurricanes change these important ecosystems.

Here are five ways scientists say the hurricanes have changed Puerto Rico’s forests since making landfall eight months ago:

1. The Canopy Is Bare

One word defines the post-hurricane forest canopy in El Yunque National Forest: Open.

“The trees have been stripped clean,” said NASA Goddard Earth scientist and G-LiHT co-investigator Doug Morton. He was there a year ago, months before the hurricanes would ravage the area. When he returned to the forest in April 2018 to gather measurements of trees on the ground to complement the airborne campaign’s lidar work, he could now see from the mountainside downtown San Juan, which is 45-minutes away by car.

And no canopy means no shade. “Where once maybe a few flecks of sunlight reached the forest floor, now the ground is saturated in light,” Morton said, adding that such a change could have profound consequences for the overall forest ecosystem. For example, some tree seedlings that thrive on a cool forest floor may whither now that daytime temperatures are as much as 4 degrees Celsius (7 degrees Fahrenheit) hotter than they were before the hurricane. Meanwhile, as we shall see, other plants and animals stand to benefit from such changes.

“Who are the winners and losers in this post-hurricane forest ecosystem, and how will that play out in the long run? Those are two of the key questions,” said Morton.

2. Palms Are on the Rise

One species that’s basking in all that sunlight is the Sierra Palm, said Maria Uriarte, a professor of ecology at Columbia University who has researched El Yunque National Forest for 15 years. “Before, the palms were squeezed in with the other trees in the canopy and fighting for sunlight, and now they’re up there mostly by themselves,” she said. “They’re fruiting like crazy right now.”

The secret to their survival: Biomechanics.

“The palm generally doesn’t break because it’s got a flexible stem—it’s got so much play,” Uriarte said. “For the most part, during a storm it sways back and forth and loses its fronds and has a bad hair day and then it’s back to normal.” By contrast, neighboring trees with very dense, strong wood, like the Tabonuco, were snapped in half or completely uprooted by the force of the hurricane winds.

“Palm trees are going to be a major component of the canopy of this forest for the next decade or so,” added Doug Morton. “They’ll help to facilitate recovery by providing some shade and protection as well as structure for both flora and fauna.”

3. Vines Are Creeping Opportunists

Rising noticeably from the post-Hurricane forest floor of El Yunque National Forest are woody vines called lianas. Rooted in the ground, their goal, Morton says, is to climb onto host trees and compete for sunlight at the top. That, combined with the fact that their weight tends to slow tree productivity potential, means they are literally a drag on the forest canopy. As lianas can wind their way around several trees, regions with more of these vines tend to have larger groupings of trees that get pulled down together.

“There’s some indication that vines may be more competitive in a warmer, drier, and more carbon dioxide-rich world,” Morton said. “That’s a hypothesis we’re interested in exploring.”

4. Endangered Parrot Populations Have Taken a Hit

The endangered Iguaca is the last living native parrot species of Puerto Rico. The island’s two Iguaca aviaries have reported a substantial number of deaths in the wild due to the hurricanes. In the forests of Río Abajo, in western central Puerto Rico, about 100 of the roughly 140 wild parrots survived; in El Yunque National Forest in the eastern part of the island, only three of the 53 to 56 wild parrots are known to have pulled through.

“It was a huge blow,” said the U.S. Fish and Wildlife Service’s Tom White, a parrot biologist stationed at the aviary in El Yunque, which took the brunt of Hurricane Maria’s Category 5 winds. Some of the parrots died from injuries received during the storm, while others likely died from increased predation from hawks because there were no longer canopies for them to hide in. The rest succumbed to starvation. The Iguaca subsists on flowers, fruits, seeds, and leaves derived from more than 60 species—but for several months following the storm, the forest was completely defoliated.

Despite the setback, White said he’s optimistic that the Iguaca will rebound. In Río Abajo, the number of wild Iguaca are enough that they should rebound on their own; in El Yunque there are about 227 birds at the aviary—a strong number for continued breeding and eventual release into the forest once conditions improve enough. “One of their main fruit comes from the sierra palm, and they’re now flowering and starting to produce again,” White noted. “It’s probably going to take about another year for things to level out, but the forest is gritty.”

5. Lizards and Frogs: A Mixed Response

When Hurricane Maria stripped the leaves off of trees, changes in the forest microclimate instantly transformed the living conditions for lizards and frogs. Species have reacted differently to the event based on the conditions they are adapted to, said herpetologist Neftali Ríos-López, an associate professor at the University of Puerto Rico-Humacao Campus.

For example, some lizard species are naturally suited to the forest canopy, which is warmer and drier. “After the hurricane, those conditions, which were once exclusive to the canopy, have now been extended down to the forest floor,” Ríos-Lopez said. “As a result, these lizards start displacing and substituting animals that were adapted to the once cooler conditions on the forest floor.”

Likewise, among frog species the red-eyed coquí, with its resistance to temperature and humidity fluctuations and its ability to handle dehydration better than other coquí species, has benefited from the warmer, drier conditions in the forests after the storm. Traditionally a grassland species, they are expanding from the lowlands to the mid- and even high parts of the mountains, Ríos-Lopez said. “Physiologically, what was a disadvantage for that species when the whole island was forested now finds itself in a positive position.” Conversely, forest-acclimated coquí frog species have declined.

That said, as the forests recover, so will many of the species whose numbers have dwindled following the storms. “It will take many years, decades, I would guess,” Ríos-Lopez said.

Our scientists are working with partners from universities and government to use G-LiHT airborne data to inform ground research on forest and other ecosystems not only in Puerto Rico but also throughout the world. To follow their campaigns and keep up with the latest news, find them here: https://gliht.gsfc.nasa.gov.

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