4-6

Delineation Drilling Activities Offshore Santa Barbara County

number of permits issued in the Pacific OCS Region

for geological and geophysical surveys by fiscal year,

1960-1990. No G&G Permits Have been issued after

1990. Table 4.0.1-2 provides the number of G&G permits issued in the Santa Barbara Channel and Santa

Maria Basin. These types of surveys are described

below.

GEOLOGICAL SURVEYS

Geological surveys include bottom sampling,

shallow coring, and drilling deep stratigraphic test

wells. Bottom samples are obtained by dropping a

weighted tube to the ocean floor and recovering it with

an attached wire line. They can also be obtained from

dredging. Shallow coring is performed by conventional

rotary drilling equipment to obtain a near-surface

sample of the rocks of the seabed. A deep stratigraphic

test, as defined in 30CFR 251.1, means drilling that

involves the penetration into the sea bottom of more

than 500 ft (152 meters). These wells are drilled primarily to gather geological information. Conversely,

shallow test drilling, as defined in the same regulations, means drilling into the sea bottom to depths

less than those specified in the definition of a deep

stratigraphic test.

GEOPHYSICAL SURVEYS

Geophysical surveys include two dimensional (2-

D) and three dimensional (3-D) deep and shallow penetration surveys, Gravity, and Magnetic surveys. shows

the number of offshore Pacific OCS 2-D and 3-D surveys conducted by decade. Table 4.0.1-3 includes 3-D

surveys conducted on lease. On lease suverys do not

require a permit. Common Depth Point (CDP) seismic information is derived from a common location in

the ocean subbottom where sound waves originating

from various positions of the seismic (sound) source

near the ocean surface are reflected back toward the

surface. The 3-D information is used to delineate, in

greater detail than that of traditional 2-D information, geologic structures that may be associated with

the occurrence of natural gas and oil. Gravity surveys

produce measurements of the gravitational field at a

series of different locations over an area of interest.

The objective in exploration work is to map density

differences that may indicate different rock types.

Gravity data usually are displayed as anomaly maps.

Fiscal Year

Total Number

of Geological

and

Geophysical

Permits

Geophysical

Permits

Geological

Permits

Permits for

Deep

Stratigraphic

Tests

3-D Seismic

Data Permits

1960-1968 153 132 21 0 0

1969 17 14 3 0 0

1970 6 5 1 0 0

1971 4 2 2 0 0

1972 4 4 0 0 0

1973 15 10 5 0 0

1974 36 29 7 0 0

1975 61 55 6 1 0

1976 32 30 2 0 1

1977 33 28 5 0 0

1978 38 30 8 1 0

1979 22 20 2 0 0

1980 31 27 4 0 0

1981 40 39 1 0 1

1982 62 60 2 0 5

1983 45 36 9 0 2

1984 56 42 14 0 8

1985 32 29 3 0 2

1986 20 19 1 0 5

1987 20 16 4 0 3

1988 33 25 8 0 2

1989 0 0 0 0 0

1990 4 3 1 0 0

Total 764 655 109 2 29

Date Geophysical Permits Geological Permits Issued

Number Issued Miles Run Sampling DST

1963 -- -- 5 --

1964 2 0.02 1 --

1965 9 7634 -- --

1966 16 9607 1 --

1967 31 880 5 --

1968 12 10,187 1 --

1969 8 2968 -- --

1970 4 2750 -- --

1971 1 80 -- --

1972 3 120 -- --

1973 6 26,700 7 --

1974 23 58,401 -- --

1975 25 38,578 2 --

1976 21 23,551 2 --

1977 19 8507 3 --

1978 23 15,309 5 1

1979 19 15,528 1 --

1980 22 33,702 -- --

1981 27 29,634 1 --

1982 28 25,614 1 --

1983 25 14,282 6 --

1984 28 16,180 8 --

1985 16 0169 1 --

1986 15 12,960 -- --

1987 10 6032 1 --

1988 9 5118 3 --

1989 0 0 -- --

1990 1 230 1 --

Total 403 379,224 55 1

* All or a portion of the survey was conducted in the Santa Barbara Channel or Santa Maria Basin area.

Table 4.0.1-1. Number of permits issued for Geological

and Geophysical Exploration in the Pacific OCS Region

from table A-10, OCS Report MMS-98-0027 and MMS

Pacific OCS Region records.

Table 4.0.1-2. Santa Barbara Channel and Santa

Maria Basin* Geological and Geophysical Permits for

the Pacific OCS Region.

Type 1960-69 1970-79 1980-89 1990-95 Total

2-D 186 147 188 3 524

3-D 0 2 30 1 33

Source, MMS 1995

Table 4.0.1-3. Offshore Pacific OCS Region 2D and

3D surveys by decade.
4-7

Description of the Affected Environment: Introduction

Magnetic surveys measure the magnetic field or its

component (such as the vertical component) at a series of different locations over an area of interest usually to locate concentrations of magnetic anomalies

or to determine depth to basement.

SITE SURVEYS FOR OCS EXPLORATION,

DEVELOPMENT, AND PRODUCTION

Site Characterization surveys are conducted on

lease to detect seafloor and subsurface geologic and

manmade hazards. Survey data is analyzed to ensure

safety of exploration and production wells and facilities and pipelines.

High-resolution or acoustic-profiling survey obtains information on the conditions existing at and

near the surface of the seafloor. On lease deep penetration seismic surveys have been conducted (table

4.0.1-3 includes four 3-D surveys conducted on lease)

Geological/geotechnical samples taken at the site

of bottom founded exploration and production platforms and within a proposed pipeline corridor are

tested to categorize foundation-engineering conditions.

Underwater video/photography, hydrocarbon

sniffer surveys, diver inspection, current velocity measurements, additional seafloor sampling and/or geologic age dating has been required to identify hazards,

archaeological resources or sensitive habitats to ensure safety of personnel and equipment and protection (or avoidance) of archaeological resources, etc.

Platforms and pipelines installed in the Pacific OCS

Region have been periodically inspected in accordance

with applicable regulations and regional Notice to Lessees and Operators. Inspections for platforms could include visual, cathodic protection, magnetic particle, or

ultrasonic testing.

Routine inspections on pipelines include visual

(diver and/or remotely operated vehicle), side scan sonar (SSS), and high resolution internal surveys.

EXPLORATION DRILLING

Exploration, as defined in 30 CFR 250.105,

means the commercial search for oil, gas, or sulphur.

Activities classified as exploration include but are not

limited to: (1) G&G surveys using magnetic, gravity,

seismic reflection, seismic refraction, gas sniffers, coring, or other systems to detect or imply the presence

of oil, gas, or sulphur; and (2) Any drilling conducted

for the purpose of searching for commercial quantities of oil, gas, and sulphur, including the drilling of

any additional well needed to delineate any reservoir

to enable the lessee to decide whether to proceed with

development and production. The drilling is usually

conducted from mobile drilling units such as a jackup,

semi-submersible, or drillship. In the Pacific OCS

Region there have been 326 exploration wells drilled,

see table 4.0.1-4.

The California State Lands Commission, http://

www.slc.ca.gov/about%5Four%5Fagency/

energy%5Fresources.htm, reports the first California

tideland oil well was drilled in 1896 in Santa Barbara

County. Within 10 years, about 400 wells could be seen

on the beach and just offshore. At that time, no State

laws governed the extraction of oil and gas from Stateowned lands and no revenues accrued to the State.

In 1921, the California Legislature authorized

the issuance of prospecting permits and leases for oil

and gas development of the State’s tide and submerged

lands by the Surveyor General, the predecessor of the

California State Lands Commission. Exclusive jurisdiction over all oil and gas development on the Stateowned property was given to the Commission by the

Legislature in 1938.

The State now administers more than 100 sites

on which oil companies have developed some 1,000

wells that take oil and gas from State lands. In addition, over 1,000 wells produce oil from granted tidelands in the city of Long Beach.

DEVELOPMENT AND PRODUCTION

Development activities include the installation

of jackets, topsides, pipelines, and drilling. Production activities include bringing the oil and gas to the

surface, handling oil and gas on the platform, and sending the oil and gas to shore. Table 4.0.1-5 shows information on Federal and State of California platforms,

pipelines and production. Table 4.0.1-6 shows information on platform construction timing, production

support activities, and decommissioning timing.

g

Lease Sale Name, Date, Area Number of Exploration Wells

Drilled

Start Date of First and Last Well

Sale P-1, 5-14-63, Northern

California

20 9-20-63 9-1-67

Sale P-2 10-1-64, Oregon and

Washington

12 4-24-65 7-11-67

Drainage Sale P3, 12-15-66, Santa

Barbara Channel

6 2-18-67 5-10-67

Sale P-4, 2-6-68, Santa Barbara

Channel

140 2-18-68 6-25-89

Sale 35, 12-11-75, Southern

California

41 7-26-76 8-25-81

Sale 48, 6-29-79, Southern

California and Santa Barbara

33 5-10-80 9-1-88

Sale 53, 5-28-81, Santa Maria Basin 55 3-21-82 6-15-86

Sale 68, 6-11-82, Southern

California and Santa Barbara

17 11-20-83 9-22-89

RS-2, 8-5-82, Santa Maria Basin 1 8-15-86 8-15-86

Sale 73, 11-30-83, Santa Maria

Basin

0 --

Sale 80, 10-17-84 Southern

California and Santa Barbara

1 12-30-89 12-30-89

Total 326*

* Does not include two Deep Stratigraphic Test wells

Table 4.0.1-4. Pacific OCS Region Exploration

Wells from USDOI, MMS, Pacific OCS Region, 1992.

Dash indicates no drilling
4-8

Delineation Drilling Activities Offshore Santa Barbara County

Platforms Pipelines Production

Peak Production: oil 

and gas 5

Structure Operator Location 1 Well 

slots1

Year Installed 

Pipelines; Size, 

Number, Type 

Year 

Installed 

Onshore 

Facility 

(pipeline 

destination) 

Field Date 1st

Prod. 

Volume 

(bbls/day) 

(MCF/day) 

Year 

Orig. 

Recoverable 

Reserves by 

Field; oil 

(MMbbl)/ gas 

(Bcf) 6

Federal Waters (All Platforms) 

Edith Nuevo Huntington 

Beach 

72 

1983 6" oil 

6" gas 

1983 

1983 

Elly 

Eva 

01/21/84 

Ellen Aera Huntington 

Beach 

80 

1980 

N/A N/A N/A 01/13/81 

Elly 2 Aera Huntington 

Beach 

Proc. Fac.2 

1980 10" water 

16" oil 

1984 

1980 

Eureka 

Beta Pump 

St. 

n/a 

Eureka Aera Huntington 

Beach 

60 

1984 

12" oil 

6" gas 

1984 Elly 

Beta 

03/17/85 

7,040,164/ 

2,698,056 

1986/ 

1985 

105.60/ 

33.5 

Gail Venoco Port Hueneme 36 

1987 8" oil 

8" gas 

8" gas 

1987 Grace Sockeye 08/08/88 3,098,035 / 

8,666,353 

1990/ 

1992 

70.83/ 

163.45

Grace Venoco Mandalay 48 

1979 10" oil 

12"/10" gas 

1980 Carpinteria 

Santa Clara 07/25/80 

Gilda Nuevo Mandalay 96 

1981 

12" oil/water 

10" gas 

6" water return 

1981 Mandalay 12/19/81 

3,037,231/ 

9,201,110 

1983/ 

1984 

49.76/ 

 80.13

Gina Nuevo Port Hueneme 15 

1980 

10" oil/water 

6" gas 

1981 Mandalay Hueneme 02/11/82 1,575,189/ 

453,060 

1983/ 

1996 

10.57/ 

5.30 

Habitat Nuevo Carpinteria 24 

1981 

12" gas 1983 Shore Pitas Point 12/15/83 33,885/ 

29,898,809 

1985/ 

1985 

0.27/ 

239.22

Hillhouse Nuevo Summerland 60 

1969 8" oil 

8" gas 

6" spare 

1969 Platform A Dos Cuadras 07/21/70 27,752,972/ 

15,483,685 

1971/ 

1971 

256.8/ 

137.6 

A Nuevo Summerland 57 

1968 12" oil 

12" gas 

6" water 

1968 B tie-in 03/03/69 

B Nuevo Summerland 63 

1968 

12" oil 

12" gas 

6" water 

6" water injection 

1968 

1968 

Rincon 

P/F C 

07/19/69 

C Nuevo Summerland 60 

1977 

6" oil 

6" gas 

6" water 

1977 P/F B 08/01/77 

 

Henry Nuevo Carpinteria 24 

1979 8" oil 

8" water 

6" gas 

1979 Hillhouse 05/15/80 

Hogan POOI Carpinteria 66 

1967 10" oil/water 

12"gas 

10" gas lift 

4" water return 

1967 La Conchita 06/10/68 

Houchin POOI Carpinteria 60 

1968 10" oil/water 

10" gas lift 

12" gas 

4" water return 

1968 Hogan 

Carpinteria 

04/28/69 

6,777,575/ 

4,749,410 

1969/ 

1969 

66.3/ 

55.0 

Pescado 18,696,920/ 

19,085,872 

1995/ 

1999 

110.79/ 

222.32

Heritage Exxon 

Mobil 

SYU 60 

1989 

20" oil/water 

12" gas 

1998 Harmony 

Sacate 12/18/93 1,886,475/ 

1,754,738 2000: 70.83/ 

163.45 

Harmony Exxon 

Mobil 

SYU 60 

1989 

20" oil/water 

12" water return 

12" gas 

1992 

1992 

Las Flores 

Hondo 

12/30/93 

Hondo Exxon 

Mobil 

Gaviota 28 

1976 

14" oil/water 

12" sour gas 

1992 

1983 

Harmony 

Las Flores 

Hondo 

04/02/81 

16,704,353/ 

38,284,266 

1996/ 

1999 

278.9/ 

834.02 

Table 4.0.1-5. Existing surface structures, pipelines, and production offshore, Southern California.
4-9

Description of the Affected Environment: Introduction

Holly (P) ARCO Goleta 30 

1966 6" oil/water 

6" gas 

1966 Elwood 

Onshore 

Processing 

facility 

S. Ellwood 1967 9,480 1984 69.4 

49 

Helen (P) Texaco Gaviota 

 

CSLC CSLC 

Cuarta 

1961 518 1962 .6 

18.7 

Abandoned 

Herman (P) Texaco Pt. Conception 

 

CSLC CSLC Conception 1961 13,703 1964 20.9 

12.3 

Removed

1

 This is the number of well slots built into the platforms. Most platforms have fewer wells than slots. 

2

 Platform Elly is an offshore processing facility to process production from Platforms E11en, Edith, and Eureka. 

3 Decommissioned 1994 

4

 The type of structure is as follows: P - Platform I - Artificial Island T - Converted Tanker d: Offshore Storage and Treatment vessel 5

 For State facilities: Peak production refers to field. Peak gas production could not be obtained. The data sourcesis the CDOGGR publication PR06 “1998 

Annual Report of the State Oil and Gas supervisor”, published in 1999. 

6

 By Field

Platforms Pipelines Production

Peak Production: oil 

and gas 5

Structure Operator Location 1 Well 

slots1

Year Installed Pipelines; Size, 

Number, Type 

Year 

Installed 

Onshore 

Facility 

(pipeline 

destination) 

Field Date 1st

Prod. 

Volume 

(bbls/day) 

(MCF/day) 

Year 

Orig. 

Recoverable 

Reserves by 

Field; oil 

(MMbbl)/ gas 

(Bcf) 6

Hermosa Arguello, 

Inc. 

Point Arguello 48 

1985 24" oil/water 

20" sour gas 

1986 Gaviota 06/09/91 

Harvest Arguello, 

Inc. 

Point Arguello 50 

1985 

12" oil/water 

8" sour gas 

1986 Hermosa 06/03/91 

Hildago Arguello, 

Inc. 

Point Arguello 56 

1986 

16" oil/water 

10" sour gas 

1987 Hermosa 

Pt Arguello 

05/27/91 

27,554,409/ 

13,092,342 

1994/ 

1994 

225.00/ 

155.33 

Irene Torch Point 

Pedernales 

72 

1985 20" oil/water 

8" sour gas 

8" water return 

1986 Lompoc Oil 

and Gas Plant 

Point 

Pedernales 

04/13/87 7,283,392/ 

2,592,970 

1989/ 

1995 

77.3/ 

25.5 

Exxon OS&T 

(T) 

Exxon Gaviota N/A 1981 

Removed:1994 6" gas 

8" water 

12" oil 

19813 Hondo n/a N/A N/A N/A

State Waters 4

Emmy a

(P) Aminoil Huntington 

Beach 

53 

1963 

8" oil/water 

4" sour gas (low) 

3" sour gas (high) 

1988 

(oil) 

1993 

(gas) 

Aera Onshore 

Processing 

Facility 

Eva (P) Unocal Huntington 

Beach 

39 

1964 

8" oil/water 

8" gas 

1984 Fort Apache 

(Huntington 

Beach) 

Huntington 

Beach 

1932 45,733 1972 583.1 

320.2 

Esther (P) Chevron Seal Beach 64 

1990 3" gas 

10" oil/ water 

1981 

(gas) 

1995 

(oil) 

Huntington 

Beach 

Monterey 

(Belmont) (I) 

THUMS Seal Beach 70 

1954 3" oil/water 

3" gas 

1954 Being 

Removed 

Belmont 

Offshore 1948 11,769 1968 63.9 

40.8 

Chaffee (I) THUMS Long Beach 393 

1966 8" oil/water 

8" gas 

12" water injection 

1966 

1993 

1966 

1993 

1966 

White Island 

Freeman (I) THUMS Long Beach 386 

1966 

8" oil/water 

6" gas 

12" water injection 

1966 White Island 

White (I) THUMS Long Beach 338 

1966 

12" oil/water 

12" gas 

18" water injection 

1987 

1966 

1966 

Grissom 

Island 

Grissom (I) THUMS Long Beach 393 

1966 14" oil/water 

12" gas 

10" water injection 

1966 Shore 

Wilmington 1939 177,468 1969 1502.5 

574 

Rincon (I) Mobil Rincon 68 

1958 6" oil 

6" gas 

1988 

(oil) 

2000 

(gas) 

Rincon 

Onshore 

Facility 

Rincon 1928 3,483 1960 36.8 

36.8 

Hope (P) Chevron Carpinteria 60 

1965 10" gas 

12" oil 

Now AGrace to 

Shore.@ 

1965 Carpinteria 

Heidi (P) Chevron Carpinteria 60 

1965 

10" gas lift 

10" gas 

10" oil 

1965 Hope 

Carpinteria 1966 28,699 1969 36.7 

40.7 

Abandoned 

Hazel (P) Chevron Summerland 25 

1958 

8" out of service oil 

6" gas 

6" oil 

1958 Carpinteria 

Hilda (P) Chevron Summerland 24 

1960 8" out of service oil 

6" gas 

6" oil 

1960 Hazel 

Summerland 1958 10,391 1964 27.5 

97.8 

Abandoned 

Table 4.0.1-5. Existing surface structures, pipelines, and production offshore, Southern

California.(continued)
4-10

Delineation Drilling Activities Offshore Santa Barbara County

Table 4.0.1-6. Existing surface structures offshore Southern California, construction timing,

production support activities, and decommissioning timing.

Platforms Construction Production and Support Activities Decommissioning 

Structure Operator Location 1 Year Installed Field Date 1st

Prod. 

Helicopter Trips 

per week with 

Yearly Total4

Crew and Supply 

Boat Trips with 

Yearly Total4

Actual or Estimated 

Removal Date 4

Federal Waters (All Platforms) 

Edith Nuevo Huntington Beach 1983 01/21/84 0 3/wk - 156/yr 

4/mo – 48/yr 

2010-2015 

Ellen Aera Huntington Beach 1980 01/13/81 2010-2015 

Elly 2 Aera Huntington Beach 1980 n/a 2010-2015 

Eureka Aera Huntington Beach 1984 

Beta 

03/17/85 

4/month – 48/yr 21/wk – 1092/yr 

3/wk – 156/yr 

2010-2015 

Gail Venoco Port Hueneme 1987 08/08/88 0 2015-2020 

Grace Venoco Mandalay 1979 07/25/80 0 

17/wk – 884/yr 

2/mo – 24/yr 2015-2020 

Gilda Nuevo Mandalay 1981 

Santa Clara 

12/19/81 0 2012-2017 

Gina Nuevo Port Hueneme 1980 Hueneme 02/11/82 0 

17/wk – 884/yr 

1/wk – 52/yr 2012-2017 

Habitat Nuevo Carpinteria 1981 Pitas Point 12/15/83 2015-2020 

Hillhouse Nuevo Summerland 1969 07/21/70 2012-2017 

A Nuevo Summerland 1968 03/03/69 2012-2017 

B Nuevo Summerland 1968 07/19/69 2012-2017 

C Nuevo Summerland 1977 

Dos Cuadras 

08/01/77 2012-2017 

Henry Nuevo Carpinteria 1979 05/15/80 

0 25/wk – 1300/yr 

1/wk – 52/yr 

2012-2017 

Hogan POOI Carpinteria 1967 06/10/68 2012-2017 

Houchin POOI Carpinteria 1968 

Carpinteria 

04/28/69 

0 21/wk – 1092/yr 

1/mo – 12/yr 2012-2017 

Heritage Exxon SYU 1989 Pescado 12/18/93 2/day – 730/yr 25/wk – 1300/yr 2020-2025 

Harmony Exxon SYU 1989 12/30/93 2020-2025 

Hondo Exxon Gaviota 1976 

Hondo 

04/02/81 

 

3/wk – 156/yr 

2020-2025 

Hermosa Arguello, Inc. Point Arguello 1985 Pt Arguello 06/09/91 2015-2020 

Harvest Arguello, Inc. Point Arguello 1985 06/03/91 2015-2020 

Hildago Arguello, Inc. Point Arguello 1986 05/27/91 2015-2020 

Irene Torch Point Pedernales 1985 Point 

Pedernales 

04/13/87 

5/day – 1825/yr 3/wk – 156/yr 

(Supply) 

2015-2020 (w/o 

Tranquillion Ridge 

Development) 

2030-2035 (with 

Tranquillion Ridge 

Development) 

Exxon OS&T (T) Exxon Gaviota 1981 

Removed:1994 n/a Removed 1994 

State Waters 3

Emmy a

(P) Aminoil Huntington Beach 1963 Huntington 

Beach 

1932 85/mo – 1020/ yr 15/mo – 180/yr 

(Work boat) 

2010-2015 

Eva (P) Unocal Huntington Beach 1964 - 20/wk – 1040/yr 

(Crew) 

2010-2015 

Esther (P) Chevron Seal Beach 1985 

Belmont 

Offshore 

1948 

- 20/wk– 1040/yr 

(Crew) 

2010-2015 

Monterey 

(Belmont) 

(I) 

THUMS Seal Beach 1954 2001 

Chaffee (I) THUMS Long Beach 1966 

Wilmington 1939 

- 

- 

14/wk– 728/yr 

1/wk– 52/yr 

Unknown 
4-11

Description of the Affected Environment: Introduction

Platforms Construction Production and Support Activities Decommissioning 

Structure Operator Location 1 Year Installed Field Date 1st

Prod. 

Helicopter Trips 

per week with 

Yearly Total4

Crew and Supply 

Boat Trips with 

Yearly Total4

Actual or Estimated 

Removal Date 4

Freeman (I) THUMS Long Beach 1966 

White (I) THUMS Long Beach 1966 

 

Grissom (I) THUMS Long Beach 1966 

- 

182/wk– 9464/yr (Crew) 

42/week – 

2184/yr (Barge) 

Rincon (I) Mobil Rincon 1958 n/a n/a 2005 

Hope (P) Chevron Carpinteria 1965 

Rincon 

Carpinteria 

1928 

1966 Removed 1996 

Heidi (P) Chevron Carpinteria 1965 Removed 1996 

Hazel (P) Chevron Summerland 1958 Summerland 1958 Removed 1996 

Hilda (P) Chevron Summerland 1960 Removed 1996 

Holly (P) ARCO Goleta 1966 S. Ellwood 1967 - 25/wk (crew) 2015-2020 

Helen (P) Texaco Gaviota 1960 Cuarta 1961 Removed 1988 

Herman (P) Texaco Pt. Conception 1960 Conception 1961 Removed 1988 

1

 Number refers to location on Figure POCS Region with Fields 

2

 Platform Elly is an offshore processing facility to process production from Platforms E11en,.Edith and Eureka. 

3

 The type of structure is as follows: P - Platform I - Artificial Island T - Converted Tanker d: Offshore Storage and Treatment vessel 4

 MMS estimates

SUPPORT ACTIVITIES

Vessels and helicopters provide transportation

of necessary supplies and personnel to offshore platforms. Table 4.0.1-6 provides present-day estimates

of vessel and helicopter support levels for production.

Records of vessel and helicopter traffic were not kept

during the development phase. Table 4.0.1-7 provides

examples of estimates of vessel and helicopter traffic

for the construction phase. The estimates are from

the EIS’s prepared for the Development and Production Plans.

Vessels are work boats and crew boats. Work

boats carry large items to the platforms and originate

from Port Hueneme. Crew boats carry personnel and

may carry small items. Crewboats originate from Port

Hueneme, Ventura Harbor, Carpenteria Pier, or

Elwood Pier.

Helicopters carry personnel and may carry small

items. Helicopters originate from the Santa Barbara

Airport or the Santa Maria Airport. The Lompoc and

Orcutt airports have also been used in the past.

Based on table 4.0.1-7 we estimate vessel and

helicopter traffic during construction: jacket and

topsides installation, hookup and commissioning, and

the initiation of drilling as follows; 1-to-6 supply boat

trips/day, 1/day to 1/week crew boat trips, and 2-to-7

helicopter trips/day.

PRODUCED WATER

A well produces an emulsion of oil and water

with gas in solution. Each platform sends the emulsion to a tank for separation of the gas. The gas is

used for fuel, sent to shore, or injected. The emulsion

may be sent to shore for processing or some or all

processing may occur on the platform.

Processing of the emulsion removes impurities

such as water and results in oil of a quality to be accepted into a pipeline for transport to a refinery. Wap g

Platform Crew Boats Supply Boats Helicopters

Gail 1

- Construction

- Drilling

2/day

1/day

1/day

1/week

2/day

2/day

Habitat 2

- Construction

- Drilling

1/day

3/day

3/week

3/week

--

3/week

Harvest 3

- Installation

- Hookup & Commissioning

- Drilling

1/day

1/day

--

4/week

4/week

3/week

3/week

3/week

1.5/day

Hermosa and Hidalgo 3

- Installation

- Hookup & Commissioning

- Drilling

1/day

1/day

--

1/day

1/day

1/day

2/week

10/week

2/day

Irene 4

- Installation/Hookup

- Drilling/Production

--

--

1 every 5 days

1 every 5 days

4 /day

7 /day

Santa Ynez Unit Platforms 5

- Installation

- Hookup & Commissioning

- Drilling

N/A

N/A

40/week

N/A

N/A

4-15/week

N/A

N/A

2/day

The term N/A means not available.

1

 Minerals Management Service, 1986.

2

 Bureua of Land Management, Army Corps of Engineers, Geological Survey, California Coastal Commission,

County of Santa Barbara, 1981.

3

 Minerals Management Service, California State Lands Commission, California Coastal Commission, and County

of Santa Barbara, 1984.

4

 Minerals Management Service, California Coastal Commission, California State Lands Commission, and County

of Santa Barbara, 1985

5

 Minerals Management Service, California State Lands Commission, and County of Santa Barbara, 1984.

Table 4.0.1-7. Estimates of vessel and helicopter

traffic during construction.

Table 4.0.1-6. Existing surface structures offshore Southern California, construction timing,

production support activities, and decommissioning timing (continued)
4-12

Delineation Drilling Activities Offshore Santa Barbara County

ter removed at a platform can be injected and/or discharged overboard in accordance with the National

Pollution Discharge Elimination System Permit

(NPDES). Water removed onshore can be can be injected onshore and/or sent to a platform offshore for

injection or overboard discharge.

Table 4.0.1-8 shows discharges of produced water from 1988 through 1999 and are based on quarterly Discharge Monitoring Reports required by EPA

as a condition of their NPDES Permit. Note, however,

the volumes reported for Platforms Hidalgo and Hogan

are for part of 1999 and not the entire year. There is

little year to year consistency of discharges. There are

a number of reasons for this inconsistency. For example, injection rates on offshore platforms vary, wells

that produce high volumes of water may be uneconomic and may be shut-in or plugged, or a platform

that pumps to another platform may cease or curtail

processing emulsion. For purposes of analysis, we assume a platform may discharge up to 330 million gallons of produced water in any year with the exception

of Platform Harmony. Platform Harmony discharges

produced water from processing of oil and gas at Los

Flores Canyon. Los Flores Canyon receives the combined production from Platforms Harmony, Heritage,

and Hondo. Platform Harmony produced water discharges were 518 million gallons in 1999. The discharge volume is not expected to increase significantly.

DECOMMISSIONING

Decommissioning is the process leading to the

removal of a production platform. Current state-ofthe-art technology (reverse installation using heavy

lift vessels) will likely be used to remove shallow water platforms. It is assumed that platforms would be

completely removed unless other options are available

in California by the State. All wells are permanently

Year Grace Gail Edith Habitat

Harmony1 Ellen/

Elly Gilda Hogan2 Irene Harvest Hidalgo Hermosa A B3 C Hillhouse4 Gina Total

1988 29.8 1.1 64 75.2 16.2 251.3 176.2 63.2 677.015

1989 24.2 5.3 10 5.4 36.2 178.4 71.2 21.1 332.3 225.5 257.6 31.3 185.4 1383.87

1990 36.3 19.5 47.6 7.8 158.5 187 65 98.4 239.9 211.2 226.3 110.9 1408.49

1991 25.9 13.6 6.9 11.5 33.6 132.6 76.3 255.4 140.6 51.9 84.4 832.651

1992 20.1 28.1 11.4 12.6 166.8 65.9 87.1 142.1 20.6 22.4 577.082

1993 4.1 49.8 11 13.5 28.2 185.4 76 7.2 243.1 87.8 23.3 131.3 1.2 861.86

1994 84.8 14.6 14.3 155.2 179.9 75.3 21.9 63.5 21 228.6 59.8 29.1 133.9 1.2 1083.085

1995 52.9 14.1 9.8 217.8 85.7 71 129.6 106.8 157.6 214.7 98.3 32.0 121.0 1311.36

1996 18.4 6.5 11.4 325.5 175 64.2 165.6 85.6 163.9 225.2 66.5 18.3 118.4 6.4 1450.91

1997 21.5 11.6 17.8 307 145.9 77.8 161.7 69.3 172.7 214.9 81.0 120.7 4.2 1406.091

1998 23.1 11.5 27.8 359 121.6 64.6 136.9 51.7 217.5 192.3 59.8 156.6 5.9 1428.392

1999 22 9.4 1.6 518 59.1 34.8 49.8 24 182.3 198.7 95.7 140.1 55.3 1390.82

Total 140.4 340.1 154.6 133.5 1910.7 228.3 1681.4 817.3 135.7 665.5 408.1 915.0 2683.6 1444.5 659.2 1171.1 322.7

1 Discharges produced water from production from Platforms Harmony, Heritage, and Hondo

2 Discharges produced water from production from Platforms Hogan and Houchin.

3 Discharges produced water from production from Platforms B and C

4 Discharges produced water from production from Platforms Hillhouse and Henery.

Source: Operator collected data submitted to EPA in required Discharge Monitoring Reports

Table 4.0.1-8. Producted water discharged by platform and by year in millions of gallons. Blank spaces are

either no data or no discharge.

plugged, severed below the seafloor, and surface casing retrieved to the platform. All piping and vessels,

including retrieved casing, are flushed, drained, and

the fluids injected or sent to shore. The components

of the topsides are removed and placed on barges. The

jacket is severed from the seafloor, lifted to the surface, and placed on a barge. Large jackets may be cut

off in smaller sections and placed on a barge. The

barges transport removed equipment, topsides sections, and jacket to a port for scrapping.

One facility in Federal waters has been decommissioned: the Offshore Storage and Treatment

(OS&T) vessel. Several facilities in State waters have

been decommissioned (see table 4.0.1-6). Table 4.0.1-

6 also provides estimated times for the decommissioning of existing facilities in Federal and State waters.

OFFSHORE TANKERING OPERATIONS

Oil spills resulting from vessel collisions and

other marine transportation-related accidents have

the potential to cause significant impacts on the marine, coastal, and human environments, and contribute to cumulative environmental impacts. Marine

transportation of Alaskan and foreign-import oil is an

activity that occurs offshore California. Table 4.0.1-9

shows volume and number of oil tankers offshore California visiting Ports of San Francisco and of Los Angeles/Long Beach and El Segundo In 2000, 877 oil tankers visited the ports of Los Angeles/Long Beach and

El Segundo. Of these tankers, 192 were United States

flagged oil tankers and 685 were foreign flagged oil

tankers (personal communication Reed Crispino,

Marine Exchange, March, 2001).

U.S. flagged oil tankers voluntarily stay 80 km

(50 mi) off the California coastline, thus avoiding the

Point Arguello platforms and the channel altogether.

In total, about 90 percent of all crude oil tankers keep

this distance. The small percentage of oil tankers that

were not seaward of 80 km (50 mi) tend to be vessels

that traverse the waters without entering a port in

California. These vessels stay more than 40 km (25

mi) from the coast (Mike VanHouten, U.S. Coast

Guard, pers. comm., April 23, 2001).
4-13

Description of the Affected Environment: Geology

Table 4.0.1-9. Marine Tankering Of Oil Offshore California

4.1 GEOLOGY

4.1.1 GEOLOGY AND PETROLEUM

POTENTIAL

The proposed action occupies two distinctly different geologic regions off the California coast. The

northern region is the offshore Santa Maria Basin.

The southern region is the Santa Barbara-Ventura

Basin. The submerged portion of the Santa BarbaraVentura Basin is commonly referred to as the Santa

Barbara Channel (Figure 1.0-1).

4.1.1.1 REGIONAL GEOLOGY – OFFSHORE

SANTA MARIA BASIN

The offshore Santa Maria Basin is approximately

100 miles (160 km) by 25 miles (40 km) in size and

occupies an area of about 2,500 sq. miles (6,400 sq.

km) (Mayerson, 1997; McCulloch, 1987). It is located

west and north of the Point Arguello area, along the

coastline of Santa Barbara and San Luis Obispo counties. The basin trends north-northwest, as do most of

its structural features (fault and fold trends). The offshore Santa Maria Basin is bounded on the east by

the Hosgri and related fault zones, on the south by

the “Amberjack High” (of Crain, et al., 1984), on the

west by the Santa Lucia Bank, and on the north by

the “San Martin Discontinuity” (of McCulloch, 1987).

As a depositional center, the basin began to form in

the late Oligocene to early Miocene [approximately

30 to 25 million years ago (mya)].

The stratigraphy of the offshore Santa Maria Basin is known from seafloor exposures, seismic methods, and boreholes drilled within the basin since 1964

(Figure 4.1.1.1-1). The stratigraphic terminology used

offshore has been adapted from the geologic literature which first described onshore exposures of the

rock formations. The distribution and nature of basement rocks within the basin is not well known.

Hoskins and Griffiths (1971) suggest that granitic

rocks, similar to those seen in the onshore Santa Maria

Basin area, may underlie portions of the offshore basin. Granitic rocks have not been identified in any of

the offshore wells, however, granite-derived coarse

clastic rocks of Cretaceous(?) to Eocene(?) age have

been identified on the Santa Lucia Bank and other

localities, suggesting a nearby granitic source. Metamorphic basement rocks of the Mesozoic (late Jurassic to early Cretaceous) Franciscan Formation have

been identified in wells and outcroppings. Magnetic

and gravity anomaly data, cited by McCulloch (1987),

indicate a complex basement rock distribution within

the basin.

1

 Tanker trips estimated from origin to destination oil volume and average tanker loads. Average tanker loads per trip estimated

from Western States Petroleum Association study “Tanker and Barge Movements Along the California Coast – 1992” by DNA

Association, Sacramento, CA, September 24, 1993.

2

 390,000 barrels/trip used to estimate Alaska crude oil southbound trips. 110,000 bbl/trip used to estimate all other oil tanker

movements.

3

 Non-persistent oil means petroleum-based oil, such as gasoline, diesel or jet fuel, which evaporates relatively quickly. Such

oil, at the time of shipment, consists of hydrocarbon fractions of which: (A) at least 50 percent, by volume, distills at a

temperature of 340 degrees C (645 degrees F); and (B) at least 95 percent, by volume, distills at a temperature of 370 degrees

C (700 degrees F).

There is no tankering of oil and gas production

from existing Pacific Region OCS oil and gas operations. All of the oil and gas produced on the OCS is

transported to shore by pipeline.

 Volume1

 (bbl) Annual Tanker Trips2

Persistent Oils 

From Alaska 193,196,481 495 

Other 38,473,754 349 

Total 231,620,235 844 

Non-Persistent Oils3 

From Alaska 931,085 8 

Other 30,674,487 839 

Total 31,605,572 847 

TOTAL 263,225,807 1,691 
4-14

Delineation Drilling Activities Offshore Santa Barbara County

The oldest sedimentary rocks within the Neogene offshore depocenter are the non-marine to shallow-marine sandstones, conglomerates and tuffs of the

lower Miocene(?) Lospe Formation and Tranquillon

Volcanics. Unconformably overlying the Lospe Formation are a succession of deep marine, fine-grained

sedimentary formations that span in age from early

Miocene to present. This succession includes the mudstones and dolostones of the lower Miocene Point Sal

Formation; the siliceous shales, porcelanites, cherts

and dolostones of the middle to upper Miocene

Monterey Formation; the diatomaceous and siliceous

mudstones of the upper Miocene to lower Pliocene

Sisquoc Formation; and the siltstones, claystones, and

sandstones of the Pliocene to Holocene Foxen and

Careaga Formations (Mayerson, 1997; Crain, et al.,

1984). The Neogene sedimentary section within the

basin varies from approximately 10,000 feet thick in

the depocenters to less than 1,000 feet thick over high

standing, eroded basement blocks (Mayerson, 1997;

McCulloch, 1987).

The bioclastic, organic-rich Monterey Formation,

was identified in the early 1900’s as a prolific source

rock for petroleum generation. In the onshore fields

of the Santa Maria basin it was noted that where the

brittle cherts and shales of the Monterey were fractured, it was also an important reservoir (Prutzman,

1913).

The Santa Maria Basin formed as a result of

rapid subsidence initiated in the late Oligocene to early

Miocene. Atwater (1970) attributed the simultaneous

formation of several offshore basins along the California continental margin to a late Oligocene encounter of an oceanic spreading center and subduction-related trench. Blake, et al. (1978) suggested that the

encounter initiated strike-slip tectonism along the

margin. Seismic records within the basin suggest that

compressional tectonics, expressed in folds and thrust

faults, became the dominant structural style by

Pliocene times.

4.1.1.2 REGIONAL GEOLOGY – SANTA

BARBARA-VENTURA BASIN

The Santa Barbara-Ventura Basin is approximately 160 miles (260 km) by 40 (65 km) miles in size

and occupies an area of about 6,400 sq miles (17,000

Figure 4.1.1.1-1. Offshore Santa

Maria Basin Stratigraphy and

Hydrocarbon Potential.

Paleogene

and / or

clastic

rocks

Cretaceous

Age Offshore Stratigraphic Unit Play

(hydrocarbon type)

Hydrocarbons source rocks reservoir rocks evidence

late early

Holocene

Pleistocene

Quaternary

Pliocene Miocene

early middle late

Neogene

Tertiary

Cenozoic

Cretaceous

Mesozoic

Jurassic(?)Paleogene

Quaternary deposits

Paleogene Sandstone

(oil)

Monterey Fractured

(oil)

Careaga Ss.

Sisquoc Fm.

Monterey Fm.

Pt. Sal Fm.

Foxen Fm.

Lospe

Fm.

Neogene breccia

Franciscan melange & local ophiolite

sandstone basal Sisquoc

oil prone

Basal Sisquoc Ss.

(oil)

oil prone (?)

volcanic rocks

Breccia (oil)

EXPLANATION

oil field

oil show in well

water-column gas anomaly

Stratigraphic unit boundaries

conformable boundary

unconformable boundary

strata not present

gradational boundary

Hydrocarbon evidence
4-15

Description of the Affected Environment: Geology

sq km). The west portion of the basin, commonly called

the Santa Barbara Channel, is submerged and comprises an area of about 2,000 sq miles (5,200 sq km).

The basin is located within the Transverse Ranges

Province, so named because of the east-west trend of

the basin’s bounding mountain ranges. Those ranges

include the Santa Ynez Mountains to the north, and

the Santa Monica Mountains and Channel Islands to

the south. The western extent of basin is less well

defined and the “Amberjack High” (of Crain et al.,

1984) is generally considered the boundary with the

offshore Santa Maria Basin.

The stratigraphy of the Santa Barbara Channel

area is known from coastal exposures, sea floor exposures, and numerous boreholes drilled offshore since

the 1890’s (Figure 4.1.1.2-1). The basin is probably

underlain by a metamorphic or metasedimentary basement complex. Schists (similar to the Catalina Schist)

and ophiolite-like rocks are noted in exposures on

Santa Cruz Island and are reported in several boreholes (Vedder, 1987). Granitic rocks have been noted

in the basin margins and granite-derived sediments

within the basin suggest the possibility of granitic

basement as well.

The oldest rocks drilled within the Channel area

date to the Mesozoic. The Mesozoic and Paleogeneaged rocked within the basin were probably deposited

in a forearc basin setting. This Cretaceous(?) to Oligocene sequence of rock formations suggest deposition within a basin adjacent to a paleosubduction zone.

Rocks of this type are widely distributed throughout

California and Baja California and are often referred

to as the “Great Valley Sequence.” A thorough review

of basement strata and the Great Valley Sequence in

the Santa Barbara Channel and adjacent areas is found

in Vedder (1987).

At some point near the end of the Paleogene,

approximately 38 to 35 mya, probably related to the

regional structural event described by Atwater (1970),

clockwise rotation of the forearc sequence began to

form the Transverse Ranges Province. Kamerling and

Luyendyk (1979) document up to 120 degrees of rotation based on paleomagnetic data. By 20 mya, the

transform boundary between the North American and

Pacific plates was the San Andreas Fault. The result

of these regional stresses resulted in the formation of

several small tectonic basins (including the Santa

Maria, Santa Barbara-Ventura, and Los Angeles basins) with localized structural complexities.

The Neogene sedimentary record indicates a predominant marine depositional environment. Microfaunal evidence in the paleontological record suggests that

deposition in the Santa Barbara-Ventura basin occurred in outer neritic to bathyal depths (S. Drewry,

personal communication). Basin subsidence continues

in the depocenters today; however, in the past 5 million years, the rate of terrigenous sedimentation has

filled the eastern portion of the basin, leaving only

the Santa Barbara Channel area submerged. Major

structural features in the basin, including the San

Cayetano, Santa Susana, and Oakridge thrust faults,

and the Ventura, Rincon, and Montalvo anticlines

suggest crustal shortening within the basin. Sylvester

and Brown (1988) indicate that several of these features may be geologically quite young (less than 1

million years old).

A regional unconformity of non-marine, transitional, and shallow marine rocks of the Sespe and

Alegria formations marks the end of the Oligocene.

During the Miocene, the sedimentary rocks record a

sudden deepening of the basin, as indicated by the

transition form the nearshore Vaqueros Sandstone to

the deepwater Rincon and Monterey Formations. The

Rincon Formation is composed of clay shales, mudstones, and siltstones. The Monterey Formation is

composed of bioclastic siliceous and phosphatic shales,

cherts, and calcareous and carbonaceous shales and

marls. Early Miocene basin-edge marine fan facies are

also noted in the record.

The Miocene to Pliocene transition is recorded

in the coeval Sisquoc and Modelo Formations. The

Sisquoc Formation is characterized by fine-grained,

terrigenous-rich diatomaceous deposits. The Modelo

Formation differs from the Sisquoc in that it contains

occasional thick sandstone beds. Blake (1988) suggests

that the increase in fine- and coarse-grained sediments

in these deepwater formations is the result global sea

level changes.

Pliocene sedimentation in the eastern portion

of the basin is characterized by an influx of coarsegrained material in volumes overtaking the rate of

subsidence and compaction. Paleobathymetric data

clearly records the shoaling of the basin. The Repetto

and Pico Formations are composed of turbidite-derived

sands, siltstones, and shales. Generally, bed thickness

and the sand-to-shale ratio of the formations increase

up-section, while the depositional environment shallows. In the western portion of the basin, turbidite

deposition is largely absent. Pliocene-aged sediments

there are generally fine-grained and derived from

nearby upland sources.

4.1.1.3 PETROLEUM POTENTIAL

The project areas in both the offshore Santa

Maria Basin and the Santa Barbara Channel are areas of proven petroleum potential. Natural oil, tar, and

gas seepage in the nearshore and offshore areas were

known to the Indian inhabitants of coastal southern

California in prehistoric times (Heizer, 1943). Early

European explorers also noted the occurrence of hydrocarbon seeps, particularly along the northern coastline of the Santa Barbara Channel (Wilkinson , 1971).
4-16

Delineation Drilling Activities Offshore Santa Barbara County

Figure 4.1.1.2-1. Santa Barbara

Channel and Ventura Basin,

Stratigraphy and Hydrocarbon

Potential.

"Sta. Marg. Ss."

middle early

Age

Offshore Stratigraphic Unit

(thickness range in play)

[equivalent unit]

Play

(hydrocarbon type)

Hydrocarbons

source

rocks

reservoir

rocks

evidence

late early

Holocene

Pleistocene

Quaternary

Pliocene Miocene

early middle late

Neogene

Tertiary

Cenozoic

Paleocene

late

Cretaceous

Cretaceous(?)

Mesozoic

Paleogene

Oligocene

Eocene

Stage1 Hallian

Wheelerian Delm. Mohnian Refugian Ulatisian

Penu.

Bul.

Ynez.

Chen. Venturian Reliz. Repettian

Late

metamorphic

rocks

undifferentiated

granitic rocks

Jalama Fm.

Pozo-Canada Fm.

undifferentiated

Camino Cielo Mbr. Anita Shale

[Juncal Fm.]

Santa Susana Fm. Llajas Fm.

Matilija Fm.

Cozy Dell Shale

Sacate Fm.

Gaviota Fm.

Alegria

Fm.

Sespe Fm.

Vaqueros Ss.

Rincon Shale

Topanga

Fm.

Monterey Fm.

Sisquoc Fm.

"Repetto Fm."

Pico Fm.

Santa Barbara & Saugus Fms.

undifferentiated

Cretaceous-Paleocene

Sandstone

(mixed)

Gaviota-Sacate-Matilija

Sandstone

(mixed)

Sespe-Alegria-Vaqueros

Sandstone

(mixed)

Rincon-Monterey-Topanga

Sandstone

(oil)

Monterey Fractured

(oil)

Pico-Repetto Sandstone

(mixed)

(0 - 10,000')

(2,000 - 10,000')

(1,000 - 4,000')

(1,000 - 3,000')

(300 - 3,000')

(100 - 2,000')

(0 - 300')

(0 - 7,500')

(0 - 8,000')

(500 - 2,000')

(1,000 - 2,500') [ "Coldwater Ss."]

(500 - 2,000')

(500 - 3,000')

(200 - 600')

(1,000 - 6,000')

(? - 6,500')

(0 - 1,500')

(1,000 - 7,500')

(? -1,000')

(?)

(0 - 1,500')

Zemorrian Saucesian Luis.

clastic

rocks

Monterey Ss. Mbr.

Narizian

gas prone (?) oil prone

oil and gas prone oil prone (?) gas prone (?)

(1,500 - 3,000')

EXPLANATION

oil field

gas field

Stratigraphic unit boundaries

conformable boundary

unconformable boundary

strata not present

gradational boundary

Hydrocarbon evidence

Stage abbreviations

Bul.

Chen.

Delm.

Luis.

Penu.

Reliz.

Ynez.

Bulitian

Cheneyan

Delmontian

Luisian

Penutian

Relizian

Ynezian
4-17

Description of the Affected Environment: Geology

Seepage oil was an important commodity to both the

Indians and the early European settlers of the region.

Fischer (1977) noted that most of the offshore seepage occurred in areas where the Monterey or Sisquoc

formations are exposed at or near the seafloor, and

where active faulting or growing folds were observed.

 Active exploration for oil began in the Santa Barbara-Ventura Basin as early as the 1860’s with the oil

tunnels dug into the seeps of the Santa Paula area.

The earliest offshore oil exploration occurred at

Summerland in the 1890’s, where the onshore field

there was extended offshore by drilling on the beach

and from piers (Galloway, 1997). Offshore oil exploration progressed in the Santa Barbara Channel area

with several coastal oil field discoveries in the 1920’s

and 1930’s. These included the Rincon, Ellwood, and

Capitan oil fields. Initially, the offshore portions of

these fields were developed by wells drilled from piers

and by wells drilled directionally from onshore locations. The prototype for the modern oil platform,

known as the “Steel Island,” was constructed on the

offshore portion of the Rincon oil field in 1931 (Galloway, 1992).

Following World War II, the advances in petroleum exploration technology (such as the invention

of mobile offshore drilling vessels and the development

of computer processing techniques for seismic reflection data) led to further exploration, discovery, and

production of the region’s hydrocarbon resources. In

the late 1940’s, 1950’s, and 1960’s several more

nearshore and offshore oil and gas field discoveries

were made. Most of these were in the Santa BarbaraVentura basin, with the exception of the Guadalupe

oil field near the mouth of the Santa Maria River.

On Federal OCS lands (those lands in excess of

three geographic miles seaward of the coast) oil exploration began in the 1950’s with the drilling of

coreholes and the mapping of the subsurface features

through the use of early seismic reflection profiling

techniques. The first Federal OCS leasing in the area

(Lease Sale P-1, 1963) included leases in the Santa

Maria basin, which led to the drilling of one oil well in

1965, approximately 12 miles southwest of Oceano

(Webster, 1983). Following a 1965 U.S. Supreme Court

decision, settling the jurisdiction over the Santa Barbara Channel area, leasing, exploration, and development of the Federal lands in the Santa BarbaraVentura basin proceeded.

Since the 1960’s, several large oil and gas fields

have been discovered and developed in and around

the project areas. Most of the proposed projects in this

EIS have been explored and have undeveloped discoveries on them.

4.1.2 GEOLOGIC HAZARDS

The principal geologic hazards in the region are

(1) earthquakes, (2) tsunamis, (3) mass wasting, and

(4) shallow gas. There exists no credible threat of local volcanic activity.

4.1.2.1 HISTORIC EARTHQUAKES

Southern California is located along a seismically

active plate margin (Figures 4.1.2.1-1. “Late Quaternary Fault Map” and Figure 4.1.2.1-2. “Seismicity

Map,” both modified after Jacobs Engineering Group,

1988). The major transform fault in the region is the

San Andreas Fault. The last significant earthquake

along the segment of the fault which borders the Santa

Barbara and Ventura county areas happened in 1857,

and is known as the “Fort Tejon” quake. Davis, et al.

(1982) postulate an 8.3 magnitude earthquake in their

planning scenario, modeled on the 1857 quake.

Several significant (Richter magnitude 6 or

greater, or Modified Mercalli intensity scale VIII or

greater) earthquakes have occurred in historic times

near the project areas. Earthquake magnitudes were

first measured on instruments in 1903. However, prior

to the 1930’s and the advent of the widespread use of

seismographs and the establishment of seismological

networks, the epicentral locations of these significant

earthquakes are conjectural.

On December 21, 1812, an earthquake centered

in the Santa Barbara county area, possibly in the western Santa Barbara Channel, damaged or destroyed

several of the old Spanish missions, including Mission La Purisima in Lompoc (destroyed), the Mission

Santa Barbara (severely damaged), and the Mission

Santa Inez (damaged). The 1812 earthquake occurred

in an area that was sparsely populated. The main

shock was preceded by about 15 minutes by a foreshock

of considerable strength. The main shock was felt over

a wide area of California. Damage from the quake

would rate approximately level IX to X on the Mercalli scale. The approximate Richter magnitude would

have been greater than 7. Mission Fathers report suspending a ball from a chain at the Santa Barbara

Presidio and watching it move continuously for

twenty-three days (George Pararas-Carayannis

website). A series of aftershocks were recorded for a

least three months following the main quake (Townley,

1939).

There are no reports of ground rupture from the

December 21 earthquake. This had led researchers to

postulate that the quake occurred along an offshore

fault, such as the North Channel Slope fault or the

offshore southern branch of the Santa Ynez fault

(Yerkes, 1980, 1981). The evidence for an offshore

source is equivocal. Recent quakes in southern California demonstrate that even large seismic events do
4-18

Delineation Drilling Activities Offshore Santa Barbara County

not necessarily produce significant surface rupture.

Interestingly, the December 21 temblor was the

second large earthquake that month to rock southern

California. On December 8, another earthquake, best

remembered for damaging the Mission San Juan

Capistrano, was noted in the Mission journals. The

December 8 shock may have been epicentered in the

Wrightwood area, on the San Andreas Fault (Townley,

1939; Jacoby, et al., 1988). It is unclear to seismologists if these earthquakes are in any way related. The

December 21 earthquake purportedly spawned a minor tsunami in the Santa Barbara Channel, which will

be discussed below.

On January 9, 1857, a great quake, with a probable magnitude of over 8 on the Richter scale, was felt

over a wide area of California, Mexico, and neighboring states. The surface rupture from this earthquake

reached from the area near Parkfield, CA, to Cajon

Pass, near San Bernardino – a distance of over 200

miles (300 km). This earthquake was preceded by two

M=6 +/- foreshocks in the Parkfield area. Shaking

during the main shock lasted up to three minutes. At

Fort Tejon and other places along the rupture, the

Mercalli intensity reached XII (highest level of destruction). In Santa Barbara, over 40 miles away from the

San Andreas fault, strong shaking lasted over one

minute, but the damage was negligible. California was

still sparsely populated in 1857 and few deaths resulted

from this quake.

A swarm of earthquakes severely damaged the

Los Alamos area of northern Santa Barbara County,

from July 27 to July 31, 1902. The largest of the temblors, on July 31, registered an intensity of VIII on

the Modified Mercalli scale. Older adobe and masonry

buildings suffered more damage than wood-framed

buildings. Noticeable aftershocks continued for several months (Townley, 1939)

In the early morning hours of June 29, 1925,

several small foreshocks rocked the Santa Barbara

area. Most residents of that city were awakened at

6:44 a.m. by the M=6.8 main shock. The shaking lasted

about 20 seconds. The epicenter of the quake was located in the Santa Barbara Channel, about 8 miles

southwest of the city. This earthquake caused considerable damage in the old business district and accounted for several deaths. The failure of the Sheffield

Dam near Santa Barbara is attributable to liquefaction of the underlying soils (Willis, 1925).

On November 4, 1927, in the pre-dawn hours a

very strong earthquake struck the offshore Santa

Figure 4.1.2.1-1. Late Quaternary Fault Map Of Western Transverse Range Region.
4-19

Description of the Affected Environment: Geology

Maria basin. This quake is alternatively known in the

literature as the “Point Arguello” earthquake or the

“Lompoc” earthquake. Both the magnitude and location of this earthquake are a source of controversy.

The quake was witnessed both on shore and at sea

(Townley, 1927; Byerly, 1930; Gawthrop, 1978; Hanks,

1979; Helmberger, et al., 1992; Satake and Somerville,

1992). Gawthrop (1978), analyzing the recorded aftershock sequence, concluded the main shock was located near the coast, possibly on the Hosgri Fault system. The recent re-analysis of the 1927 earthquake

by Helmberger, et al. (1992), and the analysis of the

related tsunami by Satake and Somerville (1992), suggest the earthquake occurred far from the coast, in

deep water, on a thrust fault related to the southern

portion of the Santa Lucia Bank fault zone.

The earthquake occurred during the pre-dawn

hours, at about 5:51 a.m. It was felt over a wide area

of southern California. The captains of two vessels

within 20 miles of the probable epicenter noted similar phenomena in their logs, including a shuddering

sensation, as if the ship was running aground. They

also noted a second seismic event 20 minutes later.

Another ship’s captain was startled to find the ocean

surface littered with dead or stunned fish later that

morning. These observations are attributable to “sea

quake” – a shock wave propagated through the water

column (Institute for Crustal Studies, UCSB, website).

Coastal and inland towns, 20-30 miles from the

epicenter, registered Mercalli intensity ratings as great

as IX to X. Reports from ranches and small communities nearest the epicenter suggest shaking strong

enough to throw objects into the air and to knock

standing people from their feet. Landslides, sand boils,

and local liquefaction gave evidence to the severity of

this quake. This earthquake spawned a small tsunami

(see below for further discussion).

A moderate earthquake, registering about magnitude 6, struck the coastal communities of Santa Barbara, Carpinteria, and Summerland at 11:50 p.m. on

June 30, 1941. The epicenter of the earthquake was

located in the Santa Barbara Channel about 2 miles

(3 km) south of Summerland (Ulrich, 1942). The slight

damage from this quake, particularly in Santa Barbara (six miles from the epicenter), is a testament to

revisions in the building codes following the 1925

Santa Barbara and 1933 Long Beach earthquakes.

A very large earthquake struck the Kern County

Figure 4.1.2.1-2. Seismicity Map Of Western Transverse Ranges Region, 1932-1982.