Experience
Since 2008 GEMS has provided marine archaeology services to our clients to meet their need for cultural resource evaluations, surveys, assessment, and reporting. Our goal is to provide the same high standard of quality, care, and professionalism in our archaeological services as we do in our other disciplines.
GEMS archaeologists assist with survey planning, survey equipment recommendations, survey QA/QC, reporting, mitigation recommendations, and governmental correspondence. Our staff has experience planning, conducting, reporting and overseeing AUV, ROV, conventional and diver assisted surveys.
Capabilities
Our staff specializes in:
- Survey planning for conventional and AUV archaeological surveys
- Shallow water surveys and assessments including equipment selection, field survey oversight, and interpretation
- Deepwater archaeological assessments for area studies, pipeline route surveys, and site specific surveys
- ROV archaeological investigations
GEMS is pleased to assist you with any archaeological assessments. Our staff is timely and professional in their operations. Our success is in identifying problems early within an area, and thus, shortening the time to complete the project. GEMS’ staff can handle all of your archaeological needs including planning, permitting requirements, setting up surveys and even mitigation actions required by the BOEM.
Shallow Water Surveys and Difficulties
GEMS archaeologists have extensive experience with planning, equipment recommendations, survey QA/QC, reporting, mitigation recommendations, and government correspondence for shallow water surveys. Our staff have conducted and/or interpreted towed equipment surveys in the Gulf of Mexico, Alaska, Suriname, Atlantic Seaboard, West Coast of Africa, East Cost of Africa and others. The equipment used for these surveys includes:
- Side-Scan Sonar
- Subbottom Profiler
- Magnetometer
- Singlebeam/Multibeam Echosounder
In addition to towed equipment surveys, we are also capable of conducting diver assisted surveys of cultural resources. GEMS archaeologists are capable of compiling all these data sets for a complete integrated report for clients. Our experience with this technology allows us to prevent or quickly solve inherent problems with collection and interpretation.
GEMS archaeologists have been involved in scientific studies of shallow water archaeological resources.
Difficulties
Murphy’s Law seems to always apply when working with equipment on the water. Even with the advancement in technology there are many inherent problems that occur while operating offshore. Shallow water surveys require the coordination of towing multiple pieces of equipment simultaneously while taking into account other vessels, ocean current, weather, and a changes in seafloor depth.
Side-Scan Sonar: There are many variables that affect the quality of the collected side-scan sonar data. In addition to altitude, speed, and frequency, environmental factors like salinity must be accounted for before survey can begin. GEMS archaeologists have experience with both processing and interpreting a wide range of data quality.
Magnetometer: Magnetometers are extremely sensitive instruments that measure the Earth’s magnetic field. For magnetometers to accurately detect magnetic anomalies it must maintain a constant height from the seafloor. BOEM regulations stipulate that towed magnetometers must not exceed 7 meters in altitude above the seafloor.
- Geomagnetic Storms: These storms are caused by solar winds generated by the sun. As these winds impact Earth’s magnetic field there are large fluctuations in the field. These fluctuations have the potential to mask anomalies and give false positives within the data set.
Subbottom Profiler: Subbottom profiler data can reveal buried relic landforms that may contain cultural material. During the last ice age much of the continental shelf was exposed and populated by Native Americans. Many of these landforms are buried, or partially eroded by the natural movement of rivers across the landscape, and can only be mapped using seismic data. GEMS archaeologists are well accustomed to interpreting these data in coordination with our geoscience staff to identify potential cultural landscapes.
Deep Water AUV Surveys
AUVs (Autonomous Underwater Vehicle) are a great tool for surveying large study areas at great depths. These vehicles can survey for up to 18-50 hours at a time while collecting multiple sets of data simultaneously. Another big advantage to using AUVs is their range of possible payloads. While side-scan sonar, subbottom profiler, and multibeam echosounder are usually standard, AUVs can be equipped with still image cameras, methane sensors, turbidity sensors, laser bathymetry systems, and AUVs are also beginning to use magnetometers.
GEMS archaeologists have extensive experience with planning, equipment recommendations, survey QA/QC, reporting, mitigation recommendations, and government correspondence for deep water AUV surveys. Our staff has conducted AUV surveys and interpreted the high-resolution data in the Gulf in the Gulf of Mexico, Mediterranean Sea, Africa and South America. The equipment used for these surveys typically includes:
- Side-Scan Sonar
- Subbottom Profiler
- Multibeam Echosounder
GEMS archaeologists are capable of compiling all these data sets for a complete integrated report for clients. Our experience with this technology allows us to prevent or quickly solve inherent problems with collection and interpretation.
Deep Water ROV Surveys
GEMS archaeologists are prepared to plan, conduct, and complete reports for ROV investigations for archaeological clearance of the seafloor. We take pride in planning for ROV surveys, insuring that the correct equipment and personnel are ready before the vessel leaves the dock. Our staff is also capable of minimizing equipment downtimes while surveying through our planning and personnel management.
Typical GEMS recommendations for ROV surveys include:
- Accurate USBL positioning of the ROV and the vessel
- Sector Scanning Sonar
- Heave Compensation
- HD lights
- Continuous recording
GEMS archaeologists are capable of compiling all these data sets for a complete ROV report for clients. Our experience with this technology allows us to prevent or quickly solve inherent problems with collection and interpretation.
