the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 25 Nov 2024
Identification of Natural and Anthropogenic Hazards within Mid-Atlantic Bight For The Purpose of Offshore Wind Turbine Foundation Recommendations
Abstract. The development of offshore wind energy in the Mid-Atlantic Bight is significantly influenced by the complex interplay of seabed topography, sediment characteristics, and human-made hazards. Utilizing seismic profiles and existing geological studies, this paper investigates the unique geological features and sediment types present in the region. These features include paleochannels, sand ridges, and varying sediment compositions, all of which have critical implications for the siting and emplacement of wind turbine foundations. The documented sediment types range from fine clays to coarser sands. Specific attention is given to glauconite sands in this research due to the unique challenges of their thixotropic behavior and potential to compromise pile capacity during installation.
In addition to natural geological factors, human-made hazards—including unexploded ordnances (UXOs), shipwrecks, and artificial reefs, are barriers to offshore wind development. The presence of these hazards necessitates careful planning and may limit available space for turbine placement. Our findings emphasize the need for enhanced geotechnical assessments and innovative foundation solutions tailored to the unique characteristics of the seabed. Regulatory frameworks that adapt to evolving understandings of seabed conditions and hazard mitigation strategies are needed to ensure the safe and efficient installation of offshore wind turbines. Ultimately, a comprehensive understanding of both natural and human-made hazards is crucial for the successful development of offshore wind projects in the Mid-Atlantic Bight to balance the economic and energy benefits against the complexities of the marine environment.
Competing interests: This research may involve competing interests across several areas. First, financial interests could exist, as BOEM, offshore wind developers, and their associated stockholders may benefit financially from the findings and recommendations provided here. Additionally, the Delaware Geological Survey (DGS) is undertaking a geologic survey of the Mid-Atlantic Bight, though the specific scale of this project is not publicly available. Personal and professional relationships may also introduce potential biases, as some of the sources referenced in this research are authored by individuals who are affiliated with or have attended the University of Delaware, where I am also affiliated. Furthermore, intellectual biases may affect my interpretations, particularly in my approach to paleochannel directions, which is informed by my experience with bathymetric contours and maritime mapping. Lastly, institutional affiliations could influence this work, as the University of Delaware, along with many offshore wind developers—especially those with projects south of New Jersey—stand to benefit from the research findings.
Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.- Preprint
(3811 KB) - Metadata XML
- BibTeX
- EndNote
Status: closed
-
AC1: 'Comment on wes-2024-157', Ophelia Christoph, 17 Dec 2024
After being told information at the recent AGU conference, slight edits to the paleochannel figure, such as Cape Charles and Exmore, need to be made. Additionally, I was provided subbottom sources for the continued paleochannel directions that confirm the direction of the channels that I would like to add to the paper.Â
An additional reference for the glauconite sand section will also be added. (Geological and Geotechnical Challenges of the East Coast United States for Offshore Energy Transition- Â D.J. DeGroot et al.)
The formatting of the references will also be changed upon manuscript resubmission.
Citation: https://doi.org/10.5194/wes-2024-157-AC1 -
RC1: 'Comment on wes-2024-157', Anonymous Referee #1, 31 Dec 2024
Comments and suggested edits can be found in the attached pdf file. General comments and suggestions hereafter:
1) The paper refers to a GIS project where all the info discussed are collected and georeferenced, however the paper does not include any mapped output. It is suggested to include and refer throughout maps of the main layers discussed (e.g. outcropping geological formations, UXO, shipwrecks, etc.). Mapped information would greatly enhance the quality of the paper, which in its current form is overly-notional and lacks specificity.
2) Some concepts and information are repeated several times within the paper. In particular Sections 6 seem to repeat many of the information reported in Sections 4 and 5. Consider revising the structure of the paper.
3) There seem to be some confusion between the concepts of 'paleo' channel (relic feature) and 'active' channel. Please revise
4) There seem to be some confusion between the concepts of seabed variability (variation of seabed level over time, irrespective of the presence of the foundations) and scouring (localised erosion due to the interaction between the foundation and the local hydrodynamic regime). Please revise
-
RC2: 'Comment on wes-2024-157', Anonymous Referee #2, 12 May 2025
The language of the paper is good but the contents largely replicate what would be done in a standard desk study and therefore although it would be of interest to those unfamiliar with that process and geohazard assessment in general it is challenging to see how this presents a unique perspective or insights. I do have concerns about how the overview and description of geotechnical design is presented in this paper and would strongly suggest that sections that focus on this aspect are rewritten. My comments below largely focus on these areas.
I have concerns about Section 5.1 and suggest that during revisions this section is completely rewritten or removed as it does not present a good overview of the geotechnical conditions that can influence foundation design (and in places is incorrect e.g. a confusing description of plasticity index is presented) - there are some great reference books available - offshore geotechnical engineering by susan gouvenec and mark randolph would be a good place to start. Â
There is also mention of seismic profiles in this section and whilst I do agree that seismic profiles are a great tool for ground modelling and targeting geotechnical exploration points and there are limitations in distinguishing between some sediment types which are critical to geotechnical design meaning that they are not necessarily a cost saving tool as stated.Â
It's also worth considering that there  are currently requirements on the minimum amount of geotechnical information that should be gathered on US projects to meet BOEM/BSEE requirements.
Later in this section there is a statement around glauconite 'behaving like quicksand' have not been demonstrated/evidenced and is misleading so I would strongly suggest this is removed.
Section 5.2 - only considers sediment movement with regards sediment addition at foundation locations which is surprising given that sediment scour around foundations is often the key concern.
Section 5.2.1 It would also be beneficial to refer to ISO/API maps of seismic hazard maps of the region which appears to be missing from this discussion and do provide guidance on how best to address the regional seismic risks as some of these statements are alarming e.g. 'Minor seismic activity could destabilize sediments...' .
Section 6.2 - I would suggest the first two paragraphs are removed/entirely re-written as they are not correct in some places. and are oversimplistic in others e.g.' clays over non-carbonate sands provide a stable base for the construction of monopile foundations.... challenges in regions where sand overlies clay'
Section 6.6 - It is not clear what point is being made in the last two sentences BOEM/BSEE do currently require consideration of foundation and cable installation risk in the COP together with consideration for UXO - this may need reframing as a section to make the discussion point clearerCitation: https://doi.org/10.5194/wes-2024-157-RC2 -
AC2: 'Replies to Reviewer's General Comments', Ophelia Christoph, 22 Jun 2025
The comment was uploaded in the form of a supplement: https://wes.copernicus.org/preprints/wes-2024-157/wes-2024-157-AC2-supplement.pdf
Status: closed
-
AC1: 'Comment on wes-2024-157', Ophelia Christoph, 17 Dec 2024
After being told information at the recent AGU conference, slight edits to the paleochannel figure, such as Cape Charles and Exmore, need to be made. Additionally, I was provided subbottom sources for the continued paleochannel directions that confirm the direction of the channels that I would like to add to the paper.Â
An additional reference for the glauconite sand section will also be added. (Geological and Geotechnical Challenges of the East Coast United States for Offshore Energy Transition- Â D.J. DeGroot et al.)
The formatting of the references will also be changed upon manuscript resubmission.
Citation: https://doi.org/10.5194/wes-2024-157-AC1 -
RC1: 'Comment on wes-2024-157', Anonymous Referee #1, 31 Dec 2024
Comments and suggested edits can be found in the attached pdf file. General comments and suggestions hereafter:
1) The paper refers to a GIS project where all the info discussed are collected and georeferenced, however the paper does not include any mapped output. It is suggested to include and refer throughout maps of the main layers discussed (e.g. outcropping geological formations, UXO, shipwrecks, etc.). Mapped information would greatly enhance the quality of the paper, which in its current form is overly-notional and lacks specificity.
2) Some concepts and information are repeated several times within the paper. In particular Sections 6 seem to repeat many of the information reported in Sections 4 and 5. Consider revising the structure of the paper.
3) There seem to be some confusion between the concepts of 'paleo' channel (relic feature) and 'active' channel. Please revise
4) There seem to be some confusion between the concepts of seabed variability (variation of seabed level over time, irrespective of the presence of the foundations) and scouring (localised erosion due to the interaction between the foundation and the local hydrodynamic regime). Please revise
-
RC2: 'Comment on wes-2024-157', Anonymous Referee #2, 12 May 2025
The language of the paper is good but the contents largely replicate what would be done in a standard desk study and therefore although it would be of interest to those unfamiliar with that process and geohazard assessment in general it is challenging to see how this presents a unique perspective or insights. I do have concerns about how the overview and description of geotechnical design is presented in this paper and would strongly suggest that sections that focus on this aspect are rewritten. My comments below largely focus on these areas.
I have concerns about Section 5.1 and suggest that during revisions this section is completely rewritten or removed as it does not present a good overview of the geotechnical conditions that can influence foundation design (and in places is incorrect e.g. a confusing description of plasticity index is presented) - there are some great reference books available - offshore geotechnical engineering by susan gouvenec and mark randolph would be a good place to start. Â
There is also mention of seismic profiles in this section and whilst I do agree that seismic profiles are a great tool for ground modelling and targeting geotechnical exploration points and there are limitations in distinguishing between some sediment types which are critical to geotechnical design meaning that they are not necessarily a cost saving tool as stated.Â
It's also worth considering that there  are currently requirements on the minimum amount of geotechnical information that should be gathered on US projects to meet BOEM/BSEE requirements.
Later in this section there is a statement around glauconite 'behaving like quicksand' have not been demonstrated/evidenced and is misleading so I would strongly suggest this is removed.
Section 5.2 - only considers sediment movement with regards sediment addition at foundation locations which is surprising given that sediment scour around foundations is often the key concern.
Section 5.2.1 It would also be beneficial to refer to ISO/API maps of seismic hazard maps of the region which appears to be missing from this discussion and do provide guidance on how best to address the regional seismic risks as some of these statements are alarming e.g. 'Minor seismic activity could destabilize sediments...' .
Section 6.2 - I would suggest the first two paragraphs are removed/entirely re-written as they are not correct in some places. and are oversimplistic in others e.g.' clays over non-carbonate sands provide a stable base for the construction of monopile foundations.... challenges in regions where sand overlies clay'
Section 6.6 - It is not clear what point is being made in the last two sentences BOEM/BSEE do currently require consideration of foundation and cable installation risk in the COP together with consideration for UXO - this may need reframing as a section to make the discussion point clearerCitation: https://doi.org/10.5194/wes-2024-157-RC2 -
AC2: 'Replies to Reviewer's General Comments', Ophelia Christoph, 22 Jun 2025
The comment was uploaded in the form of a supplement: https://wes.copernicus.org/preprints/wes-2024-157/wes-2024-157-AC2-supplement.pdf
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 258 | 95 | 23 | 376 | 25 | 35 |
- HTML: 258
- PDF: 95
- XML: 23
- Total: 376
- BibTeX: 25
- EndNote: 35
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1