Why in the news?

  • A 2025 study in Global and Planetary Change discovered 117-million-year-old mud waves buried beneath the Atlantic seabed near Guinea-Bissau.

Mud Wave

  • What is it?
    • A mud wave is a large, wavelike sedimentary structure found on the deep ocean floor, composed mainly of fine-grained mud.
    • They are typically formed by the slow movement of bottom currents that transport and deposit fine sediments over time.
  • Location and Occurrence
    • Common in abyssal plains, continental rises, and areas near deep-sea channels.
      Found in regions with steady but gentle thermohaline circulation or contour currents.
    • Examples: North Atlantic Ocean (near Mid-Atlantic Ridge flanks), areas influenced by Antarctic Bottom Water.
  • Formation Process
    • Suspension Settling: Fine particles settle from the water column to the seafloor.
    • Bottom Current Influence: Slow, persistent deep currents (contour currents) redistribute sediments.
    • Wave-like Shapes: Alternating ridges and troughs form perpendicular to current direction, creating a “wavy” seabed.
  • Characteristics
    • Wavelength: Several hundred metres to kilometres.
    • Height: A few metres to tens of metres.
    • Composition: Predominantly clay and silt.
    • Stability: Form slowly and remain stable over long geological timescales.
  • Geographical Importance
    • Indicator of paleocurrent directions in deep ocean.
    • Act as sediment traps, storing organic carbon and influencing deep-sea ecology.
    • Useful in submarine geology and oil/gas exploration studies.