Pacific - Very Long

(1) Peru Chile (2500 miles long) (4124 fathoms long)

(2) Mindanus Trench (5738 fathoms)

(3) Marrana Trench (5936 fathoms)

(4) Tonya Trench (5810 fathoms)

(5) Ranapo (Japan) (5510 fathoms)

(6) Vitiog (Marrana 6000 fathoms) not confirmed

(7) Middle American Trench

Gulf of Cable to Panama


Shape much


Extent submarine volcano there

Trenches and Island Arcs - Crustal movement involved - Earthquakes most

common in this area, shallow crust quake

Island arc and volcanoes also

Lines of Volcanoes parallel trenches arc shaped island also associated gravity pull

greater under trenches lies under lands

Sea Mount & Griyots

Sea mountains & extinct volcano lava cools quickly and gives a very steep slope

approximately 100 volcanic (basaltic)

Griygot - Flat top and terraced sides - can't be explained by volcanism - possibly

flat mountains at or near sea level - waves cut summit quickly (ash & scorea)

Coral reef can add to flat top by growth - also shares a sediment margin but can't

find any rimmed coral (Marshalls/ Gilberts on slope)

Possibility of Submergence

(1) Subsidy ocean floor and sea level use

(2) Lava release - gas for H20 ocean floor sand and H20 added (regional


Shelf Study Methods & Instrumentation

(1) Gravimetric

(2) Magnetometic

(3) Corers

(4) Drudges

(5) Diving - Lung, Hard Hat

30 fathoms average depths (oil area)

man 200 feet and (50 fathoms)

Jacques Cousteau

Peter Stenurt

General Info:

Average Width = 42 miles

Average Depth = 72 fathoms

Average Depth of flat areas = 32 fathoms

Average slope =10 fathoms per mile

Dispute of Continual Shelf and off Shore Limits

US - 12 mile (3mile)