Microseism Energy Harvesting Study
Abstract
It has been known since the work of Longuet-Higgins in the early 1950s [1] that the source of sea-floor microseisms (i.e. micron-scale displacements of the sea-floor) is the downwardtraveling second-order pressure waves that are generated when two oppositely traveling surfacegravity waves on the ocean interact. The second-order pressures do not attenuate with water depth, so their effect can be produced in ocean depths of 2000m or more. The amplitudes ofthe second-order pressures is proportional to the product of the amplitudes of the oppositely traveling waves. The microseisms can carry most energy when the second-order pressure waves have a resonant interaction with the natural vertical oscillation modes of the ocean-water column extending down to the sea-floor. The microseisms can travel long distances over the sea-floor and can be detected on the coast. Although the power in the second-order pressurewaves is considerably smaller than the power carried by the interacting surface waves, our calculations show that it can be on the order of watts to hundreds of watts, depending on whether or not a resonant interaction occurs.Microseism energy does not appear to have received much attention in the open literature, however, and the goal of the research proposed here is to evaluate these power levels and their geographic distribution. If the power levels prove appreciable over most of the year at key locations, then this phenomenon could represent a potentially useful source of energy at the sea-floor in the deep oceans. The work proposed is expected to proceed in the followingprincipal steps. A more detailed break-down is included in the proposal sections. Identify 5 locations ((near-shore and mid-ocean) worldwide in consultation with the ONR Program Office. For yearly wave climates at these locations, evaluate energy availability on the sea-floor Weexpecttoaccomplishthesegoalsintwophases. PhaseIwillfocusonanear-shorelocationwitheasilyavailablewellquantifiedwavedata(real-timeandhistorical)areavailable. Havingestablished sufficient confidence in the analysis procedureand themodeling tool that results,wewillproceedtootherkeylocationswherewavedataarelessreadilyavailableandwherewemayneedtorelyonhind-castdata.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 31, 2020
- Source ID
- N000142012785
Entities
People
- Umesh A. Korde
Organizations
- Johns Hopkins University
- Office of Naval Research
- United States Navy