OFFSHORE SAND PROSPECTING IN HAWAII James H. Barry Sea Engineering, Inc. Waimanalo, HI Honolulu, Hawaii Makai Research Pier, Waimanalo, Hawaii Santa Cruz and Santa Barbara, California www.seaengineering.com
ABOUT US Coastal & Ocean Engineering, Marine Construction, Diving Huki Pono Huki Pau SEA ENGINEERING, INC. WAS FOUNDED IN 1973 BY UNIVERSITY OF HAWAII GRADUATE STUDENTS TO PROVIDE MARINE-RELATED ENGINEERING, CONSTRUCTION AND DIVING SERVICES. TODAY, WE HAVE FOUR OFFICE LOCATIONS IN HAWAII AND CALIFORNIA AND OVER 80 EMPLOYEES. OUR CLIENTS INCLUDE PROFESSIONAL, BUSINESS AND INDUSTRIAL FIRMS; MARINE CONTRACTORS; GOVERNMENT AGENCIES (STATE, FEDERAL, COUNTY) AND RESEARCH INSTITUTIONS. Honolulu, Hawaii Makai Research Pier, Waimanalo, Hawaii Santa Cruz, California www.seaengineering.com
Why Offshore Sand Prospecting? Ka`anapali, Maui 2003 Kuhio Beach, Waikiki HAWAII BEACH SAND IS VIRTUALLY ALL CARBONATE DERIVED FROM OFFSHORE SOURCES ON-LAND SOURCES EXIST, BUT ARE LIMITED OR NOT AVAILABLE COASTAL EROSION IS A GROWING CONCERN AND CERTAIN AREAS HAVE CRITICAL NEEDS
EARLY RESEARCH OVERVIEW: Involved Organizations 1968-1978 1988-1994 1993-1994 University of Hawaii (HIG) State of Hawaii, Marine Affairs Coordinator Sea Grant (NOAA) USACE Pacific Concrete and Rock Company, Ltd. Ocean Innovators (Fred Casciano) Marine Minerals Technology Center (MMTC - U.S. Bureau of Mines) Edward K. Noda & Associates (State Department of Transportation) Sea Engineering /Precision Signal (CEROS) MMTC 1996-2000 USGS/Sea Engineering 2000 - Present Sea Engineering UH Coastal Geology Group USACE Reconnaissance Sand Surveying and Sampling Surveying of Select Deposits Instrument Development Deposit Mapping and Characterization (Oahu) Deposit Mapping and Characterization (Oahu and Outer Islands)
EARLY RESEARCH: Offshore Sand Mapped Around Oahu GENERAL CONCLUSIONS: SAND DEPOSITS OCCUR IN ALLUVIAL CHANNELS AND WAVE-CUT TERRACES GROUND-TRUTH JET PROBES REVEALED THAT DEPOSITS ARE OFTEN THINNER THAN SHOWN BY GEOPHYSICS OFFSHORE SAND IS GENERALLY TOO FINE FOR BEACH NOURISHMENT, BUT SELECT LOCATIONS HAVE REASONABLE GRAIN SIZE CHARACTERISTICS OFFSHORE SAND IS GENERALLY GRAY IN COLOR PROSPECTING: 1. LOCATE SAND: SIDE SCAN AND MULTIBEAM SONAR, GEOLOGICAL INSIGHT, DIRECT OBSERVATION 2. DETERMINE SAND THICKNESS: SUB-BOTTOM PROFILING AND PROBING 3. DETERMINE GRAIN SIZE CHARACTERISTICS: VIBRACORE SAMPLING
EARLY RESEARCH: POOR QUALITY DATA
1993-1995: SEI & PRECISION SIGNAL INSTRUMENT DEVELOPMENT: CHIRP SUB-BOTTOM SONAR FUNDED BY CEROS (CENTER OF EXCELLENCE FOR RESEARCH IN OCEAN SCIENCES) DESIGNED BY STEVE SCHOCK AND LESTER LEBLANC PRECISION SIGNAL, INC. (NOW PART OF EDGETECH) SPECIFICALLY FOR HAWAIIAN SAND DEPOSITS 0.4-10 khz VARIABLE PULSE ACOUSTIC BAFFLING TO REDUCE NOISE WIDE 2-CHANNEL RECEIVE ARRAY
1996-2001: USGS OAHU SURVEYS U.S. Geological Survey Open-File Report 03-441 Geology of Reef-Front Carbonate Sediment Deposits around Oahu, Hawaii by Monty A. Hampton 1, Charles T. Blay 2, Christopher Murray 3, Laura Z. Torresan 1, Cathy S. Frazee 1, Bruce M. Richmond 1, and Charles H. Fletcher 4 1 U.S. Geological Survey, Menlo Park, CA 2 TEOK Investigations, Poipu, HI 3 Battelle Pacific Northwest National Laboratory, Richland, WA 4 University of Hawaii, Honolulu COMPREHENSIVE GEOPHYSICAL SURVEYING AND VIBRACORE SAMPLING AROUND OAHU
1996-2001: USGS OAHU SURVEYS Vibracore 31V1, north coast Massive-appearing (bioturbated), pebbly, medium- to very coarse-grained, algal/coral/foraminiferal carbonate sand: grayish orange (10YR7/4); very poor sorting; sand and pebble size clasts rounded to well rounded; composed mainly of a mix of calcareous algae (47.5%), coral fragments (15.5%) and foraminifera (11.0%); common carbonate rock fragments (8.5%) and mollusks (11.0%).; light olive gray (5Y6/1);; composed mainly of a mix of coral fragments (38.5%), calcareous algae (28.5%) and foraminifera (16.0%); common carbonate rock fragments (6.0%), minor echinoid fragments (3.0%), mollusks (2.0%) and Halimeda (2.0%). VIBRACORE 31
REEF TOP SAND: WAIKIKI DRAWING AND NOTES FROM CONSTRUCTION PLANS MAPPED BY UH COASTAL GEOLOGY GROUP (UHCGG) AND SEI USING AERIAL PHOTOGRAPHS, JET PROBES, AND GEOPHYSICS TYPICALLY 4-6 FT IN THICKNESS BEING USED FOR 24,000 CY NOURISHMENT OF KUHIO BEACH (JANUARY 2012) TOYO PUMP FOR SAND RECOVERY
SEI SURVEYS: RECENT WORK KA`ANAPALI SURVEYS FOR KA`ANAPALI OPERATIONS ASSOCIATION (2008) KAHULUI FOR MOFFETT & NICHOL / COUNTY OF MAUI (2008) POIPU / KAPA`A FOR COUNTY OF KAUAI (2011) WINDWARD AND NORTH SHORE OAHU NEARSHORE REEF CHANNEL DEPOSITS (2013)
SEI SURVEYS: KA`ANAPALI (2008) COMPREHENSIVE SONAR SURVEYS, PROBING, AND VIBRACORE SAMPLING FOUND EXTENSIVE DEPOSITS SUITABLE FOR BEACH NOURISHMENT MOST SAND COMPOSED OF HALIMEDA CALCAREOUS GREEN ALGAE HALIMEDA MEADOW
SEI SURVEYS: KAHULUI (2008) TYPICAL SUB-BOTTOM IMAGE SURVEY CONDUCTED TO PROSPECT FOR SAND SOURCE FOR NORTH SHORE OF MAUI EMERGENCE OF LIMESTONE SUBSTRATE
SEI SURVEYS: POIPU (2011) SURVEY CONDUCTED AS PART OF ON- GOING COMPREHENSIVE STUDY OF POIPU BEACH: POIPU BEACH PARK RESTORATION STUDY (COUNTY OF KAUAI) VIBRACORING CONDUCTED IN NOVEMBER, 2011
SEI SURVEYS: POIPU (2011)
SEI SURVEYS: POIPU (2011)
SEI SURVEYS: KAANAPALI (2008) Kaanapali Beach Sand vs Vibracore Samples 100 Mean -20% 20% V1BP0-4 V1BP4-8 90 V2BP*0-2 V2BP*0-3 80 V3BP0-2 V3BP2-4 V3BP4-6 70 V3BP6-8 V4BP0-6 % Finer Than by Weight 60 50 40 30 V5BP2-4 V5BP6-8 V6H4-6 V7SW*0-4 V7SW*4-6 V8SW*0-8 V9H0-2 V9H6-8 V10SW0-2 V10SW2-4 V10SW4-6 20 V10SW6-8 V11SW0-2 10 V11SW6-8 V12H0-2 V13BP0-4 1.2 1 0.8 0.6 Size (mm) 0.4 0.2 0 0 V14BP*0-2 V15H2-4 V16SW2-4 V16SW4-6 Figure 5-3: Kaanapali Beach Sand vs Vibracore Samples Note: Green = Halimeda sand, Blue = Kekaa Point sand, Red = Sand Wave area sand
ALOHA