Site WP-2B | Table of Contents


Site: WP-2A
Site Location Map
Seismic Line

Priority: 1
Position: 41°04.79´N, 159°57.78´´E
Water Depth: 5548 m
Sediment Thickness: ~420 m
Target Drilling Depth: 600 mbsf
Approved Maximum Penetration: 800 mbsf
Seismic Coverage: Intersection of KH96-3 Leg 1 Line 2-4 with Line 2-1

Objectives: The objectives of Site WP-2A are:

1.Install long-term borehole seismic observatory to monitor global seismicity.

2.Core 100 m of the upper basaltic oceanic crust to add knowledge of MORB chemistry and emplacement.

3.Determine Pacific plate paleolatitude and tectonic drift.

4.Determine nature of Cretaceous basement and age of Anomaly M8.

Drilling Program: APC to 180 mbsf, XCB to refusal (200 mbsf), RCB to 100 m into basement (~600 mbsf). Drill instrumented borehole to ~600 mbsf, install reentry cone, and case through unstable section

Logging and Downhole Operations: Triple combo, FMS/sonic/temperature, BHTV; install long-term sensor package and cement at the bottom

Nature of Rock Anticipated: Upper layer ~310 m thick of biogenic silica-bearing clay and dark brown pelagic clay; lower layer ~110 m thick of interbedded radiolarian chert, porcelanite, and siliceous clay, 100 m of basalt flows and pillow basalts

Site WP-2B | Table of Contents