# The Glacier That Bleeds (DD-725)

> Blood Falls is a sporadic outflow of brine at the snout of Taylor Glacier in the McMurdo Dry Valleys, where the glacier ends at ice-covered Lake Bonney. Griffith Taylor found it in 1911, and its color was first blamed on red algae. The source is ancient seawater, concentrated by freezing and sealed beneath the glacier. Estimates range from about 1.5 million years of isolation (for the microbes living in it) to a Pliocene origin about 5 million years ago. The brine is salty, iron-rich and has no detectable oxygen. When it reaches the air, dissolved ferrous iron oxidizes into iron-rich nanospheres that stain the ice red as the brine drops 60 to 80 feet to the lake shore. A 2017 radar survey traced a brine pathway more than 300 feet long inside the glacier, making Taylor the coldest known glacier with persistently flowing water.

- Department: Nature (also Locations)
- First published: 2026-07-01
- Last updated: 2026-07-01
- Permalink: https://detailenjoyer.com/case/the-glacier-that-bleeds/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## On the timeline

- **About 5 million years ago**: A Pliocene marine incursion likely leaves the seawater that becomes Blood Falls' brine
- **1911**: Griffith Taylor discovers Blood Falls, and its color is first blamed on red algae
- **2017**: A radar survey traces a brine pathway more than 300 feet long inside Taylor Glacier
- **2023**: An analysis finds the red comes from iron-rich nanospheres, not crystalline rust

Full timeline: https://detailenjoyer.com/timeline/?case=the-glacier-that-bleeds

## Quick facts

- **DD-725-F01**: Blood Falls is red because iron-rich, oxygen-free brine from beneath Taylor Glacier oxidizes the moment it meets the air. _(Write-up · Exhibit A (Where it is))_
- **DD-725-F02**: The brine stays liquid inside a glacier whose mean temperature is about -17 °C, because salt lowers its freezing point and freezing releases heat. _(Write-up · Exhibit F (Liquid inside a cold glacier))_

## Write-up

Antarctica's glacier that seems to bleed. Iron-rich brine from beneath Taylor Glacier rusts red the moment it meets the air.

1. **Where it is**: Blood Falls is at the snout of Taylor Glacier, an outlet of the East Antarctic Ice Sheet that ends in Lake Bonney in the McMurdo Dry Valleys. The red brine drops 60 to 80 feet to the shore of the frozen lake.
2. **Not algae**: Griffith Taylor discovered it in 1911, and the color was first attributed to red algae. It actually comes from iron in brine that reacts on contact with air.
3. **Ancient seawater**: The brine's chemistry matches seawater concentrated by freezing. It's thought to be a remnant of a Pliocene marine incursion about 5 million years ago, and its microbes have been isolated for an estimated 1.5 million years.
4. **No oxygen**: At its source the outflow is iron-rich (3.8 mM total iron) and has no detectable oxygen. Microbes inside it survive by cycling iron and sulfur compounds.
5. **Why red**: A 2023 analysis found no strong evidence of crystalline rust minerals. Instead, the color comes from amorphous, iron-rich nanospheres that form as dissolved iron oxidizes in air.
6. **Liquid inside a cold glacier**: Radar traced a brine pathway more than 300 feet long inside the glacier. The brine stays liquid because salt lowers its freezing point and freezing releases latent heat, making Taylor the coldest known glacier with persistently flowing water.

## Related case files

- [Dead Pools (DD-049)](https://detailenjoyer.com/case/dead-pools/): Another ancient brine: seafloor pools so salty and dense they don't mix with the water above.
- [Heavenly Lake (DD-019)](https://detailenjoyer.com/case/heavenly-lake/): Another remote lake with a story: Blood Falls spills onto frozen Lake Bonney, while Namtso sits 4,718 m up in Tibet.
- [Foreverest (DD-063)](https://detailenjoyer.com/case/foreverest/): More from Extreme Cold: on Everest's summit, January averages about -36 °C.
- [Danakil Depression (DD-055)](https://detailenjoyer.com/case/danakil-depression/): Another landscape colored by iron-rich brine: Blood Falls, stained red as its iron oxidizes in air.
- [Guttation (DD-064)](https://detailenjoyer.com/case/guttation/): Another strange liquid that seeps out of nature: brine flowing from Taylor Glacier.
- [Iceberg Blue (DD-299)](https://detailenjoyer.com/case/iceberg-blue/): I paired it with another glacier with a surprising color
- [Glacial Waterfalls (DD-316)](https://detailenjoyer.com/case/glacial-waterfalls/): I linked more glaciers
- [Rainbow Mountains (DD-646)](https://detailenjoyer.com/case/rainbow-mountains/): Iron oxide doing the coloring

## Reel vs. record

- **Confirmed from the frames**: the Reel is about Blood Falls at Taylor Glacier (captions at 0.8–4.0 s). Iron-rich, hypersaline, oxygen-free brine emerges and turns red on contact with air. [Mikucki & Priscu 2007; UAF]
- **Missing detail**: it doesn't flow constantly. Blood Falls releases brine sporadically, and the red stain persists between releases. [Badgeley et al. 2017; Cambridge]
- **Refined**: it isn't simply 'rust'. A 2023 study found no strong evidence of crystalline iron oxide; the red comes from amorphous iron-rich nanospheres that form as the dissolved iron oxidizes. [Frontiers 2023; Johns Hopkins]
- **Roughly right**: 'trapped for millions of years.' Estimates range from about 1.5 million years of isolation to a seawater origin about 5 million years ago, and UAF says 'more than 1 million years'. [NASA Astrobiology; Mikucki & Priscu 2007; UAF]
- **Footage note**: the wide shots of a towering ice wall and branching red veins across a frozen plain appear dramatized and may be AI-generated or heavily edited. The real feature is a rust-red stain where brine drops 60 to 80 feet to the shore of Lake Bonney. [frames; Cambridge]

## Video: The Glacier That Bleeds: Antarctica's Glacier That Seems to Bleed

- Duration: 22.8 s · Published: 2026-07-01
- File: https://detailenjoyer.com/assets/videos/DaQZZtfRH9D.mp4

### Transcript

DID YOU KNOW? Blood Falls is a waterfall at the front of Taylor Glacier in Antarctica, where deep red water flows from beneath the ice, creating the appearance of blood spilling onto the frozen landscape. The unusual color comes from iron-rich, hypersaline water that has been trapped beneath the glacier for millions of years. When this oxygen-poor brine reaches the surface, the dissolved iron reacts with oxygen in the air and rapidly oxidizes. NOW YOU KNOW!

## Questions & answers

**Q: Which glacier is Blood Falls on?**  
A: It's in the McMurdo Dry Valleys, ending at Lake Bonney. _(Source: Write-up · Exhibit A (Where it is) · Badgeley et al., An englacial hydrologic system of brine within a cold glacier: Blood Falls (Journal of Glaciology, 2017); Solving the mystery of Antarctica's 'Blood Falls' (Cambridge Core Blog, 2017))_

**Q: What was the red color first blamed on?**  
A: Griffith Taylor found the falls in 1911. _(Source: Write-up · Exhibit B (Not algae) · Researchers solve the century-old mystery of Blood Falls (University of Alaska Fairbanks); Solving the mystery of Antarctica's 'Blood Falls' (Cambridge Core Blog, 2017))_

**Q: What makes the brine turn red?**  
A: It forms iron-rich nanospheres. _(Source: Write-up · Exhibit E (Why red) · Sheffer et al., A Multi-Technique Analysis of Surface Materials From Blood Falls (Frontiers in Astronomy and Space Sciences, 2023); Seeing red: Researchers uncover the century-old mystery of Blood Falls (Johns Hopkins Hub, 2023))_

**Q: How much oxygen is in the brine at its source?**  
A: Microbes survive by cycling iron and sulfur instead. _(Source: Write-up · Exhibit D (No oxygen) · Mikucki & Priscu, Bacterial Diversity Associated with Blood Falls (Applied and Environmental Microbiology, 2007); Life at Blood Falls (NASA Astrobiology, 2009))_

**Q: Why doesn't the brine freeze inside the glacier?**  
A: Taylor is the coldest known glacier with persistently flowing water. _(Source: Write-up · Exhibit F (Liquid inside a cold glacier) · Badgeley et al., An englacial hydrologic system of brine within a cold glacier: Blood Falls (Journal of Glaciology, 2017); Researchers solve the century-old mystery of Blood Falls (University of Alaska Fairbanks))_

## Sources

- [Badgeley et al., An englacial hydrologic system of brine within a cold glacier: Blood Falls (Journal of Glaciology, 2017)](https://doaj.org/article/bd333f16254645f5a2ec94cda8d7d1f4)
- [Researchers solve the century-old mystery of Blood Falls (University of Alaska Fairbanks)](https://www.uaf.edu/news/archives/news-archives-2010-2021/researchers-solve-the-100-year-old-mystery-of-blood-falls.php)
- [Mikucki & Priscu, Bacterial Diversity Associated with Blood Falls (Applied and Environmental Microbiology, 2007)](https://journals.asm.org/doi/full/10.1128/aem.01396-06)
- [Sheffer et al., A Multi-Technique Analysis of Surface Materials From Blood Falls (Frontiers in Astronomy and Space Sciences, 2023)](https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2022.843174/full)
- [Seeing red: Researchers uncover the century-old mystery of Blood Falls (Johns Hopkins Hub, 2023)](https://hub.jhu.edu/2023/06/26/blood-falls-mystery/)
- [Life at Blood Falls (NASA Astrobiology, 2009)](https://astrobiology.nasa.gov/news/life-at-blood-falls/)
- [Solving the mystery of Antarctica's 'Blood Falls' (Cambridge Core Blog, 2017)](https://www.cambridge.org/core/blog/2017/05/04/solving-the-mystery-of-antarcticas-blood-falls/)

## Cite this case file

Easterling, Marcus. "The Glacier That Bleeds." The Detail Department (DetailEnjoyer), case file DD-725, last updated Jul 1, 2026. https://detailenjoyer.com/case/the-glacier-that-bleeds/