Science Center Objects

USGS uses the vibracorer is best in locations where the seafloor, lakebed, bay-floor, or river-bottom sediment is unconsolidated and waterlogged.

People stand on the deck of a ship while guiding a large seafloor coring device off the stern, mountains in background.

USGS science crew position the Rossfelder vibracorer for deployment off San Francisco, California.

Photo credit: Jamie Conrad, USGS

Description  

The Rossfelder P-5 vibracorer is designed for penetrating unconsolidated, waterlogged sediments in the ocean, lakes, harbors, bays, and rivers. The P-5 houses a pair of vibrator motors in a contra-rotating configuration that doubles the vertical motion of the unit. Single barrels of 2.5m - 4m are attached to the head and a flexible “float and lead foot” package assist in keeping the corer upright during the operation. The high-frequency, low-amplitude vibrational energy is emitted from the vibracore head down through the attached barrel, liquifying the sediment and enabling the core barrel to penetrate. The core sample is captured in an internal polybuterate liner, and is retained by a cutter nose and core catcher.

Specifications

  • Manufacturer - Rossfelder 
  • Model – P-5 
  • Weight – Head – 325 lbs, weight of system – 800 lbs. 
  • Dimensions –  20’ x 3’ x 3’ 
  • Power Requirements - 15kva, 3 phase, 480v power. 
  • SWLs - 5 ton SWL

Operational Characteristics

Photo of the stern of a ship on the water with equipment tied down to the deck and coastal cliffs in the background.

The vibracorer’s polybuterate liner is visible. More liners can be seen in a cage off to the side.

Photo credit: Jamie Conrad, USGS

  • Operational Depth – to 600m water depth
  • Sediment Type – unconsolidated, waterlogged sediments
  • Limitations – relatively light weight of corer limits penetration of dewatered sediments and thick sand deposits
  • Ship’s Requirements
    • A-frame height of at least 24’ (for 4m barrels)
    • Ship’s generator providing adequate power
    • Ability to hold station for duration of operation, at least 10 minutes

Additional Equipment Required

  • Core pipe, polybuterate liner, cutter noses, core catchers