The British Institutions
Reflection Profiling Syndicate



The British Institutions Reflection Profiling Syndicate (BIRPS), founded in 1981, acquires, processes and interprets seismic data from the lithosphere.

The data are collected using commercial contractors and are publicly released. The BIRPS Core Group was an expert group which not only oversaw the collection and processing of the data, but also provided technical advice on:

* Regional tectonic settings

* Crustal evolution

* Integrated seismic experiments

* Wavefield propagation

* Data inversion


Recent and Current Projects

Chicxulub Experiment
Impacts and Extinctions: profiling the smoking gun

3-D EPR
Integrated 3-D imaging of an overlapping spreading centre
on the East Pacific Rise

FIRST
Falkland Islands Regional Seismic Traverse


Data Acquisition

Since its inception, BIRPS has collected over 20,000 km of deep seismic data recorded to at least 15 s two-way travel-time. Most of these data were acquired around the British Isles along offshore profiles designed to cross the likely continuation of major structures known from surface geology on-land. During the past decade BIRPS has also undertaken projects on a worldwide basis to help understand the geology of the UK by surveying modern day analogues and to address specific targets of interest to research workers in the UK. The high quality of the data has been ensured by the use of commercial contractors working to stringent quality control specifications.

Major discoveries and achievements of BIRPS include:

* Discovery of discrete reflections from the mantle
* Imaging of post-orogenic basins
* Evidence for reactivation of older structures
* Estimation of physical properties of the crust and upper mantle
* Imaging of Proterozoic (1900 Ma) plate boundaries



Integrated Experiments

BIRPS has extensive experience mounting integrated experiments that record the seismic wavefield, both P- and S-waves, at all offsets from near-normal incidence to wide-angle using land and sea-bed instrumentation.


(Data reduced at 8 km/s)




Interpretation

The long profiles acquired as part of the BIRPS project are ideal for regional tectonic interpretations. These show how the major structures formed in the lithosphere control the subsequent evolution on a local scale. Structures related to previous orogenic events can control basin geometry and infill. Mapping of the crust has given evidence for the behaviour of major faults at depth and provided evidence to support rheological models of the lithosphere.


(Data recorded off the north coast of scotland)



Technical Innovation

BIRPS was a centre of expertise in the understanding of methods of data inversion, data processing and wavefield propagation. Inversion algorithms, developed as part of the BIRPS project, are used to derive robust velocity models and independence structure from both near-normal and wide-angle data. This information can readily be incorporated into migration imaging and petrophysical models.


Geological exposures show complexity at all length scales. Continuing research explores the effects of small scale random scattering on the wavefield and methods of analysis.

Velocity Tomogram


Academic & Industry in Co-operation

BIRPS was sponsored by the Natural Environment Research Council, the BIRPS Industrial Associate Scheme and other affiliated projects.

Industrial Associate Scheme members 1995-1998

Amerada Hess Ltd

Arco British Ltd

BP Exploration Operating Co Ltd

British Gas Plc

Chevron UK Ltd

Conoco (UK) Ltd

Lasmo North Sea Plc

Mobil North Sea Plc

Shell UK Exploration & Production

Statoil (UK) Ltd


BIRPS

University of Cambridge
Department of Earth Sciences
Bullard Laboratories, Madingley Road,
Cambridge CB3 OEZ, UK

Tel: + 44 (0) 1223 360376
Fax: + 44 (0) 1223 360779