# Iceberg Blue (DD-299)

> Glacier ice forms as snow is buried and compressed over years, squeezing out air bubbles. Ice and water absorb a little more red light than blue, so over long paths through clear ice, red is removed and the light that comes back looks blue. Snow and bubbly ice look white because countless surfaces scatter all colors before much is absorbed. So deep, dense, bubble-free ice in a glacier or iceberg looks the most blue. The footage shows a glacier front calving blue ice into the sea.

- Department: Nature (also Science)
- First published: 2024-08-14
- Last updated: 2024-08-14
- Permalink: https://detailenjoyer.com/case/iceberg-blue/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-299-F01**: Ice absorbs slightly more red light than blue. _(Write-up · Exhibit B (Red is absorbed))_
- **DD-299-F02**: Bubbles make ice look white. _(Write-up · Exhibit D (Why snow is white))_

## Write-up

Dense glacier ice glows blue. Ice absorbs red light, so thick, bubble-free ice looks blue.

1. **Compressed snow**: Glacier ice forms as buried snow is compressed and air is squeezed out.
2. **Red is absorbed**: Ice absorbs slightly more red light than blue.
3. **Long light paths**: Over long paths through clear ice, the remaining light looks blue.
4. **Why snow is white**: Bubbles and grain surfaces scatter all colors, so snow looks white.
5. **Deepest blue**: Dense, bubble-free ice looks the most blue.

## Related case files

- [The Glacier That Bleeds (DD-725)](https://detailenjoyer.com/case/the-glacier-that-bleeds/): I paired it with another glacier with a surprising color
- [Emperor Penguins (DD-115)](https://detailenjoyer.com/case/emperor-penguins/): I linked more from the polar ice
- [Polar (DD-119)](https://detailenjoyer.com/case/polar/): I linked more from the polar ice
- [The Fingers of Death (DD-264)](https://detailenjoyer.com/case/the-fingers-of-death/): I linked more polar ice
- [What Are You Waiting For? (DD-273)](https://detailenjoyer.com/case/what-are-you-waiting-for/): I linked more snow and ice
- [To Break the Ice (DD-318)](https://detailenjoyer.com/case/to-break-the-ice/): I linked more sea ice

## Reel vs. record

- **Note**: 'Scatters the shorter wavelengths': I'd put the emphasis on absorption. The blue comes mainly from red being absorbed along long paths through clear ice; scattering by bubbles makes ice look white, not blue.

## Video: Iceberg Blue: Dense Glacier Ice Glows Blue

- Duration: 23.9 s · Published: 2024-08-14
- File: https://detailenjoyer.com/assets/videos/C-q803rpnmx.mp4

### Transcript

DID YOU KNOW? The deeper blue color of iceberg's ice further down is due to the way that light interacts with the ice. As light penetrates the ice, the ice absorbs more of the longer wavelengths reds and yellows, and scatters the shorter wavelengths the blues. This effect is enhanced in denser, older ice which has fewer air bubbles and impurities. The clearer purer ice deep within the iceberg absorbs more red light and reflects more blue light creating a richer deeper blue color! NOW YOU KNOW!

## Questions & answers

**Q: How does glacier ice form?**  
A: Air bubbles are squeezed out. _(Source: Write-up · Exhibit A (Compressed snow) · Wikipedia: Blue ice (glacial))_

**Q: Which light does ice absorb more?**  
A: The difference is small but adds up. _(Source: Write-up · Exhibit B (Red is absorbed) · Wikipedia: Blue ice (glacial); Wikipedia: Color of water)_

**Q: Why does thick clear ice look blue?**  
A: Blue light remains. _(Source: Write-up · Exhibit C (Long light paths) · Wikipedia: Blue ice (glacial))_

**Q: Why is snow white?**  
A: Little light is absorbed. _(Source: Write-up · Exhibit D (Why snow is white) · Wikipedia: Blue ice (glacial))_

**Q: Which ice looks the most blue?**  
A: Light travels farther through it. _(Source: Write-up · Exhibit E (Deepest blue) · Wikipedia: Blue ice (glacial))_

## Sources

- [Wikipedia: Blue ice (glacial)](https://en.wikipedia.org/wiki/Blue_ice_(glacial))
- [Wikipedia: Color of water](https://en.wikipedia.org/wiki/Color_of_water)

## Cite this case file

Easterling, Marcus. "Iceberg Blue." The Detail Department (DetailEnjoyer), case file DD-299, last updated Aug 14, 2024. https://detailenjoyer.com/case/iceberg-blue/