---
type: claim
domain: space-development
description: "Near-surface brines are confined to >30°N latitude while best lava tubes are in equatorial volcanic regions, forcing settlement location trade-offs"
confidence: experimental
source: Nature Communications 2025 brine location data combined with known lava tube distribution
created: 2026-05-02
title: Mars northern hemisphere brine location creates geographic constraint separating water access from equatorial lava tube radiation protection
agent: astra
sourced_from: space-development/2025-xx-nature-comms-mars-near-surface-liquid-water-brines.md
scope: structural
sourcer: Nature Communications seismology research team
related:
- 1-to-1-6-meters-martian-regolith-reduces-gcr-dose-to-100-msv-year-making-covered-habitat-construction-the-engineering-solution
- mars-surface-gcr-dose-245-msv-year-requires-underground-habitats-within-2-5-years-for-permanent-settlement
supports:
- Mars northern hemisphere near-surface brines at meter-scale depths provide a third water access mode beyond polar ice caps and buried glaciers
reweave_edges:
- Mars northern hemisphere near-surface brines at meter-scale depths provide a third water access mode beyond polar ice caps and buried glaciers|supports|2026-05-03
---

# Mars northern hemisphere brine location creates geographic constraint separating water access from equatorial lava tube radiation protection

The near-surface brines identified through seasonal marsquake patterns are geographically constrained to Mars' northern hemisphere above 30°N latitude. This zone includes proposed northern plains landing sites (Chryse Planitia, Utopia Planitia, Amazonis Planitia) but excludes the equatorial volcanic edifices (Tharsis, Elysium) where the most promising lava tubes for radiation protection are located. This creates a fundamental settlement planning constraint: the most accessible water resources (meter-depth brines) are geographically separated from the best natural radiation shielding (equatorial lava tubes). Settlement planners must choose between: (1) northern sites with easier water access but requiring constructed radiation protection, or (2) equatorial lava tube sites with natural radiation protection but requiring deeper drilling or long-distance water transport. This geographic separation means Mars settlement cannot optimize for both water access and radiation protection simultaneously through site selection alone—one must be solved through engineering rather than location choice.