NASA Imagery Details Twice-Daily Tidal Shifts in Guinea-Bissau Archipelago
Satellite imagery from NASA and the USGS highlights how daily tides reshape Guinea-Bissau's Bijagós Archipelago, temporarily expanding island landmasses during low tide.
A satellite image captured on November 28, 2025, showcases the dramatic environmental changes caused by natural tidal shifts in Guinea-Bissau’s Bijagós Archipelago. Released by NASA and the U.S. Geological Survey (USGS), the aerial photograph documents how twice-daily water movements alter the shape and size of the West African coastal landforms.
The Bijagós Archipelago consists of 88 islands and islets flanked by sandy channels, expansive mudflats, and dense mangrove forests. Twice every day, incoming and outgoing tides move through this intricate marine and coastal maze, transforming the visible terrain.
During low tide, extensive intertidal mudflats and sandflats emerge above the surface of the Atlantic Ocean. This temporary exposure causes the individual islands to grow significantly in visible land area. Within hours, as the tide rises again, the ocean waters submerge these flats, shrinking the landmass back to its high-tide contours.
The imagery captured by NASA's Lauren Dauphin and the USGS provides detailed insight into the dynamic geography of the archipelago. The region's fluctuating intertidal zones play a vital role in supporting local coastal ecosystems and wildlife.
Source attribution
- nasa.govHQ Web Team
Original source links
- nasa.gov: Original source
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Tags
Guinea-Bissau · Bijagós Archipelago · NASA · USGS · Environment · Tides
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