How are equal-area projections of earth inaccurate ?

Answer 1

Equal-area projections of the Earth are inaccurate in some ways because they necessarily distort shapes, angles, or distances. They are designed to preserve the relative areas of different regions on the Earth's surface, but this preservation of area means that other properties of the regions are not accurately represented.

1. Shape distortion: Equal-area projections often distort the shapes of landmasses, making them appear elongated or compressed compared to their actual shapes. This is because shapes cannot be preserved accurately while also preserving area.

2. Angle distortion: Equal-area projections usually introduce angular distortion, causing the angles between lines on the map to be distorted. This means that straight lines on the Earth's surface may appear curved or bent on the map.

3. Distance distortion: In equal-area projections, distances between points on the Earth's surface are often distorted. As the map expands or contracts different areas in order to maintain equal areas, the distances between points get stretched or compressed. This can result in inaccuracies when trying to measure actual distances between locations.

4. Tiling issues: Most equal-area projections cannot be seamlessly tiled or laid side by side without introducing additional distortions. This makes it difficult to create a globally consistent representation of the Earth's surface using equal-area projections.

It's important to note that these inaccuracies are trade-offs for accurately representing area, as no single projection can accurately depict every aspect of the Earth's surface simultaneously. Different map projections are used for various purposes based on the types of distortions they introduce.