Expedition scientists 8 countries
Expedition 319: Key Scientific Results
Riser borehole: Measure stress and pressure. Conduct imaging study of plate boundary (W-VSP). Develop protocls for cuttings measurements. Activity, history of megasplay Install monitoring sensors in megasplay fault
Drill Site Locations Megasplay site Riser drill site above locked fault
- Control of borehole pressure - Deeper drilling - New tools & measurements - Stress, pressure - First time in IODP history Riser Drilling:
(Front view) (Rear view) MDT Tool: Successful Stress, Pressure Measurement
Stress directions and Magnitude Combined result from new data and Stage 1 boreholes Indicate changes in stress regime possibly related to locked fault below
Stress directions and Magnitude Narrow region of stress rotation above megasplay fault Provides clues about fault behavior beneath the drill sites
Stress directions and Magnitude Narrow region of stress rotation above megasplay fault Provides clues about fault behavior beneath the drill sites
Geologic History of Kumano Basin Cores and drill cuttings Provide clues about activity and geologic history
Size fractions from washed cuttings Woody fragments Chips of hard sediment
Cuttings Lithologic Components
Washed cuttings, 1-4mm, “silty clay” Unit III Unit IV
Geologic History of Kumano Basin Cores and drill cuttings
Geologic History of Kumano Basin Age of sediment: records rapid filling of the Kumano Basin Provides clues about activity and history of the Megasplay fault
Megasplay Drillsite:
Successful Installation of Retrievable Subseafloor Observatory: Monitoring the Megasplay
Retrievable Observatory “Smartplug”
At the wellhead: 2.5 km below sea level
Primary Results New information on stress conditions above the locked plate boundary fault zone; achieved by riser drilling. New information about history of Mega-splay fault system. First observatory sensors installed by D/V Chikyu, and first observatory in NanTroSEIZE project.
One Science Party, Two “Shifts”