Developing a site survey for scientific ocean drilling on the Mauritanian continental margin
Lead Research Organisation:
Newcastle University
Department Name: Sch of Natural & Environmental Sciences
Abstract
Large volumes of methane, a potent greenhouse gas, are stored on continental margins in shallow waters (e.g. <500m). These deposits, referred to as methane hydrates are widespread on continental margins and are considered to be one of the largest methane reservoirs that naturally exist. There is evidence from the geological record on the Mauritanian continental margin that potentially large volumes of methane have been released as a result of the methane hydrate destabilisation due to past increases in ocean temperatures and this will have entered the oceans and perhaps the atmosphere. The release of methane from hydrates during a warming world has been suggested previously be an important mechanism for changing the chemistry of the oceans and amplifying climatic change.
The proposed project here will identify candidate scientific drilling sites to investigate the potential contribution that different climatic changes and different escape pathways might have on methane hydrate systems. The International Ocean Drilling Programme (IODP) is focused on addressing key questions about the Earth's history, in particular, understanding the connections between components of the Earth systems. This project will identify specific sites where scientific ocean drilling could provide the required data to understand in detail, the distribution of gas hydrates and how such a system responds to climatic shifts.
The proposed project here will identify candidate scientific drilling sites to investigate the potential contribution that different climatic changes and different escape pathways might have on methane hydrate systems. The International Ocean Drilling Programme (IODP) is focused on addressing key questions about the Earth's history, in particular, understanding the connections between components of the Earth systems. This project will identify specific sites where scientific ocean drilling could provide the required data to understand in detail, the distribution of gas hydrates and how such a system responds to climatic shifts.
Publications
Davies R
(2023)
Long-distance migration and venting of methane from the base of the hydrate stability zone
in Nature Geoscience
| Description | Our work looked to build on previous research on methane hydrates offshore of Mauritania, West Africa. Buried beneath the oceans surrounding continents is a naturally occurring frozen form of methane and water. Sometimes dubbed "fire-ice" as you can literally set light to it, marine methane hydrate can melt as the climate warms, uncontrollably releasing methane - a potent greenhouse gas - into the ocean and possibly the atmosphere. The work we undertook during the grant allowed us to estimate the amount of methane hydrate that is vulnerable to warming is higher than previously thought. The release from the seabed could cause the oceans to become more acidic and the climate to warm further. Our work identified that the massive venting of methane from similar ancient marine hydrate reservoirs has been linked to some of the severest and most rapid climate changes in the Earth's history. Through the project we undertake a detail mapping of the potential sites offshore West Africa where scientific expeditions could, in the future, use the combination of site specific geophysical studies, together with drilling, to provide the most detailed calibration of this complex interaction between the geology, oceans and climate. |
| Exploitation Route | The site specific studies we hope will be able to be used as part of future IODP planning. |
| Sectors | Energy Environment |
| Title | Output from the modelling of the depths of the BHSZ |
| Description | This is the output of the modelling of the depth of the base of the hydrate stability zone (BHSZ) for the modern BHSZ and the BHSZ during from the Last Glacial Maximum. It is not the complete dataset, it is 65536 lines long. We can include the full dataset at a later stage. The methodology is outlined in Methods. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://springernature.figshare.com/articles/dataset/Output_from_the_modelling_of_the_depths_of_the_... |
| Title | Model BHSZ LGM |
| Description | Model used to calculate the position of BHSZM and BHSZR. Model uses an empirical expression for the gas hydrate phase boundary, assuming pure methane and a seawater salinity of 35‰ |
| Type Of Technology | Software |
| Year Produced | 2023 |
| URL | https://data.ncl.ac.uk/articles/software/Model_BHSZ_LGM/24164157 |
| Title | Model BHSZ LGM |
| Description | Model used to calculate the position of BHSZM and BHSZR. Model uses an empirical expression for the gas hydrate phase boundary, assuming pure methane and a seawater salinity of 35‰ |
| Type Of Technology | Software |
| Year Produced | 2023 |
| URL | https://data.ncl.ac.uk/articles/software/Model_BHSZ_LGM/24164157/1 |
| Description | Article - The Conversation |
| Form Of Engagement Activity | Engagement focused website, blog or social media channel |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | Richard Davies produced an article for The Conversation based on the outputs of a linked research publication. https://theconversation.com/frozen-methane-under-the-seabed-is-thawing-as-oceans-warm-and-things-are-worse-than-we-thought-216054 |
| Year(s) Of Engagement Activity | 2023 |
| URL | https://theconversation.com/frozen-methane-under-the-seabed-is-thawing-as-oceans-warm-and-things-are... |
