Articles

A scene of a 17th century map where the country is in the shape of a lion.

Zoomorphic Maps: Imagining Maps as Animals

Rebecca Maxwell

These zoomorphic maps were designed as propaganda tools, with each one depicting the world in a way that reflected the message the cartographer intended to convey.

A chestnut-backed chickadee on a redwood branch.

Number of “Dees” in a Chickadee’s Alarm Call is Related to the Danger Level of Nearby Predators

Caitlin Dempsey

The number of "dees" in a chickadee's alarm call correlates with the size and threat level of the predator.

The Earth can be divided into two main systems: the geosphere and the biosphere. Image: USGS, public domain.

What are the Earth System’s Four Spheres?

Caitlin Dempsey

The systems of the earth can be divided into two main areas: geosphere and biosphere.

Using Seals to Track Ocean Currents

Caitlin Dempsey

By tagging seals with specialized sensors, researchers can map Antarctic ocean currents, heat distribution, and assess the health of marine ecosystems.

A black and white dragonfly resting on a blade of grass.

Tracking Mercury With Dragonflies

Caitlin Dempsey

Published research mapped mercury levels in dragonfly larvae from 73 U.S. parks, revealing how the metal accumulates in the environment.

A photo of an ashen area with steam coming out of a geyser.

Hydrothermal Explosions

Caitlin Dempsey

Hydrothermal explosions are dramatic, natural events that occur when superheated water and steam are suddenly released from beneath the Earth's surface.

Tourists with cameras photography a grizzly bear crossing the road.

The Recreational Value of Nature and Wildlife

Mark Altaweel

Measuring the economic benefits of wildlife and outdoor areas supports conservation with tools like the NPS Visitor Spending Effects.

Gravity wave clouds over a forest on a bright sunny day.

How Undular Bores Show Up in the Clouds

Caitlin Dempsey

Undular bores create distinctive wave-like cloud patterns, such as morning glory clouds, by pushing warm air upward.

A giant sequoia tree at Yosemite National Park's Mariposa Grove of Big Trees.

Geography of Giant Sequoias

Elizabeth Borneman

Giant sequoias are one of the longest lived tree species, with the oldest giant sequoia living an estimated 3,400 years.

A lizard clinging upright on a steep rock with dried grass behind it.

Urbanization is Shortening the Legs of Western Fence Lizards

Caitlin Dempsey

Western fence lizards have adapted to manmade surfaces in urban areas by developing shorter limbs and toes.

An American robin on a tree branch.

Most Abundant Landbird in the United States and Canada

Caitlin Dempsey

The American robin has the largest population among all landbirds in the United States and Canada.

McKinley Lake near Cordova, Alaska

Which States Have the Highest Percentage of Water Area?

Caitlin Dempsey

Water shapes U.S. states' geography and ecosystems. Which states have the highest and lowest percentages of area covered by perennial water?

The Diomedes Islands mark the closest point between Russia and the United States.

These Two Countries are Separated by 2.4 Miles and 21 Hours

Caitlin Dempsey

There exists a geographic point where two of the largest countries in the world are only separated by a 2.4 miles but are 21 hours apart.

A fox squirrel lying with legs stretched in the grass.

Why Do Squirrels Lie Flat?

Caitlin Dempsey

There are several reasons for why squirrels will lie flat on the ground, a patio railing, or tree branch.

The color of water is a by product of how light is absorbed. Mangrove islands bespeckle the bay in upper Lostman's River. Photo: Paul Nelson, U.S. Geological Survey. Public domain.

How Mapping Mangrove Species Can Help With Coastal Erosion Mitigation

Mark Altaweel

Species-specific mangrove maps aid conservation by targeting protection efforts and resources against storm surges and coastal erosion.

Screenshot from QGIS showing a satellite image of a beach with red dots and triangles for types of nesting sites.

How to Find the URL to an ArcGIS Online Web Map and Add it to QGIS

Caitlin Dempsey

Learn how to find URLs for older feature and map servers hosted on ArcGIS Online so they can be added to QGIS.

A yellowed map of the Philadelphia area from the 1800s.

Chorology and Chorography

Caitlin Dempsey

Chorology examines places and regions, often known as regional geography, while chorography focuses on describing or mapping those regions.

Screenshot of a raster file geodatabase in QGIS.

How to Use Esri File Geodatabases in QGIS

Caitlin Dempsey

Learn how to load both Esri vector and raster file geodatabases in QGIS.

Screenshot in QGIS of a world map with smiley face emojis mapped across it.

Little Known QGIS Parlor Tricks

Caitlin Dempsey

The coordinate box in QGIS is one place where you can uncover neat little GIS Easter eggs.

A screenshot showing the stylized Q for QGIS with a bold dark blue arrow pointing towards the Applications folder on a Mac.

How to Install QGIS on a Mac Computer

Caitlin Dempsey

Follow these step-by-step instructions on how to install QGIS on a Mac.

Map showing the location of Alert, Canada. Data from Naturalearth.com, map by Caitlin Dempsey.

What to Know About Absolute and Relative Location

Caitlin Dempsey

Understand absolute and relative location: absolute uses coordinates or fixed points, while relative describes a place in relation to another location.

A white sign with black writing indicating it's a witness post.

Witness Posts

Caitlin Dempsey

Witness posts are signs that alert visitors to the presence of a nearby survey marker.

An abnormal growth of leaves in a conifer tree.

Witch’s Broom in Trees: Dense Clump of Leaves and Branches

Caitlin Dempsey

Witch's broom affects trees like birch, spruce, and pine, causing dense twig and leaf clusters due to pathogens, parasites, and environmental stressors.

A map of the southwest region of the US showing in deep red extreme heat across the area.

Mapping Heatwaves from Space: How Extreme Temperatures Are Modeled

Caitlin Dempsey

The Goddard Earth Observing System (GEOS) model can help researchers predict and map heatwaves around the world.

Side by side satellite images of a glacier in 1988 and 2015 showing the glacier shrinking.

Venezuela Becomes the First Country to Lose its Glaciers

Caitlin Dempsey

Venezuela became the first country to lose all of its glaciers as the last remaining ice on Pico Humboldt shrank to less than two hectares.

An annotated satellite image of a white icy area.

Understanding Fast Ice in Polar Ecosystems and Climate Dynamics

Caitlin Dempsey

Fast ice, found in both polar regions, is sea ice that attaches to coasts, icebergs, ice shelves, or the ocean floor.