The PAP observatory is situated in the Northeast Atlantic away from the continental slope and Mid Atlantic Ridge. The site is an open ocean time-series representing processes in the North Atlantic Drift Region and accessible from many EU ports.

Latitude and Longitude: 49.0°N 016.5°W
Depth: 4850m
Oceanographic Region: Northeast Atlantic

Physical setting: The PAP observatory lies south of the main stream of the North Atlantic Current and is subject to return flows from this coming from the West and Northwest. An intermittent stream of cyclonic and anticyclonic mesoscale eddies cross the site extending sometimes several thousand metres into the water column. The winter condition at the site is of a mixed layer as deep as 800m driven by convective overturning although throughout the winter there are short periods of stability during which the mixed layer may only be a few tens of metres thick.

The PAP sustained observatory is about 300 miles southwest of Ireland.

Ocean observatories measure properties of the seawater such as temperature, salinity and carbon dioxide. They can continuously record data every few hours for weeks, months and even years.

Observatories are typically made of a single column of strong wire stretching from the sea surface to the sea floor. Scientific instruments, sensors, are attached in clusters like mini constellations all the way down the wire. Sensors can also be attached to equipment including landers that are positioned on the seafloor. The equipment remains submerged in seawater for months on end, transmitting information by satellite or storing information inside the sensor until it is picked up by scientists venturing out to sea.

Variable (*r-t) Depths measured (m) Sensor(s) used
Atmosphere/Sea surface (from 2010)
Wind speed and direction atmosphere Gill acoustic sensor and revolution magnetic compass
Relative humidity atmosphere Rotronic Hygroclip R/S sensor
Air and sea surface temperature atmosphere and surface (approx. 1.5m depth) Electrical Resistance Thermometer (ERT)
Atmospheric pressure atmosphere Druck RPT350 pressure sensor
wave height/period surface Datawell heave sensor (17.5 min average)
Water column (autonomous since 2002)


(2002–2008 additional microcats from 40–1000m)
40, 60, 75, 90, 110, 130, 150, 200, 250, 300, 1000

Microcat (Seabird SBE-37 IMPs)


(2002–2008 additional microcats from 40–1000m)
40, 60, 75, 90, 110, 130, 150, 200, 250, 300, 1000

Microcat (Seabird SBE-37 IMPs)
Chl-A* 25* Fluorometer (WETLabs FLNTUSB; Turner Cyclops)
Nitrate* 25*


NAS3 (chemical) not functioning since Sept 2010

PAR* (Irradiance) surface* and 25* Satlantic OCR-507 ICSW and OCR-507 R10W + Bioshutter2
Dissolved CO2* 25* ProOceanus CO2-Pro
Dissolved O2 25 (new in 2010; no real-time since Sept 2010) Aandera optode
Current 25 (new in 2010; no real-time since Sept 2010) Aanderaa RCM (30m) ADCP (4800m)
Turbidity* 25* WETLabs FLNTUSB
Pressure* 25* Microcat + fluorometer
POC (sub-surface mooring) 3000, 3050, 4700 McLane Sediment Trap
Zooplankton sampler 25 (testing in 2009 and May–September 2010) McLane ZPS
Total dissolved gas pressure 25* ProOceanus GTD-Pro
  Seafloor (4800m depth) since 1989  
Images seafloor digital camera (time-lapse)
Marine fauna seafloor e.g., trawls, corers, camera, hydrophone
Sediment (geochemistry) seafloor trawls, corers, camera

Since 1989, this environmental study site in the Northeast Atlantic has become a major focus for international and interdisciplinary scientific research and monitoring including water column biogeochemistry, physics and benthic biology. Since 2002, a mooring has been in place with sensors taking a diverse set of biogeochemical and physical measurements of the upper 1000m of the water column.

One of the very few images of HMS PorcupineOne of the very few images of HMS Porcupine

Some of these data are transmitted in near real-time via satellite. The PAP site is now part of the EuroSITES network of European Deep ocean observatories which will integrate and enhance nine time-series sites and carry out science missions to develop new sensors and techniques for observing the changing oceans.

The name ‘Porcupine’

The name ‘Porcupine’ is taken from the naval survey vessel HMS Porcupine which was engaged on scientific expeditions in the NE Atlantic and Mediterranean in 1869 and 1870. She make the first ever deep ocean dredge for living creatures in 1869 resulting in the naming of the Porcupine Bank off the west coast of Ireland. The Porcupine Abyssal Plain is the deep flat region to the south of the Porcupine Bank.

Cruises to the PAP site

Below is a list of the cruises to the PAP site from 1989 to the present.

Cruise Principal Scientist Affiliation Start date
RRS Challenger 6A/85     31/06/1985
RRS Challenger 8/86     25/11/1986
Discovery 185 A.L. Rice IOS 18/08/1989
Challenger 79 A.L. Rice IOS 12/05/1991
Challenger 94     29/07/1992
Meteor 21/1 H. Thiel Hamburg University, Germany 16/03/1992
Charles Darwin 72 R.S. Lampitt IOS 24/08/1992
Poseidon 200/7 B. v Bodungen IFM-GEOMAR, Kiel, Germany 23/06/1993
Challenger 111 B.J. Bett IOS 29/03/1994
Charles Darwin 85 P.R. Pugh IOS 11/04/1994
Meteor 30/1 O. Pfannkuche IFM-GEOMAR, Kiel, Germany 07/09/1994
Discovery 217 R.S. Lampitt IOS 27/09/1995
Discovery 222/1 I.G. Priede Aberdeen University 27/07/1996
Meteor 36/4 G. Graff GEOMAR, Kiel, Germany 20/08/1996
Discovery 222/2 A.L. Rice SOC 29/08/1996
Meteor 36/5 Ch. Hemleben IFM-GEOMAR, Kiel, Germany 07/09/1996
Meteor 36/6 O. Pfannkuche IFM-GEOMAR, Kiel, Germany 09/10/1996
Discovery 226b A.L. Rice SOC 12/03/1997
Discovery 229 B.J. Bett SOC 02/07/1997
Challenger 134     11/08/1997
Challenger 135 D.S.M. Billett SOC 15/10/1997
Discovery 231 A.L. Rice SOC 28/02/1998
Meteor 42/2 O. Pfannkuche IFM-GEOMAR, Kiel, Germany 17/07/1998
Discovery 236 I.G. Priede Aberdeen University 23/08/1998
Pelagia 123 G. Duinveld NIOZ, Netherlands 02/09/1998
Discovery 237 M. Sibuet IFREMER, France 24/09/1998
Challenger 147c R. Lampitt SOC 04/10/1999
Discovery 250     18/09/2000
Discovery 251T E.B. Cooper SOC 31/03/2001
Discovery 252     13/04/2001
Discovery 255     14/08/2001
Discovery 260     06/03/2002
Discovery 266 D.S.M. Billett SOC 27/09/2002
Poseidon 300/1 R. Lampitt SOC 06/07/2003
Poseidon 306 T. Mueller IFM-GEOMAR, Kiel, Germany 09/11/2003
Charles Dawin 185 R. Lampitt SOC 15/06/2004
Discovery 284-T     02/09/2004
Discovery 295&6 R. Lampitt NOC 05/07/2005
Discovery 306 P. Burkill NOC 23/06/2006
Celtic Explorer 0716 R. Lampitt NOC 19/06/2007
James Cook JC34T C. Day NOC 18/05–03/06/2009
Discovery D341 R. Sanders NOC 09/07–12/08/2009
James Clark Ross R. Lampitt NOC 26/5–06/06/10
Celtic Explorer J. Campbell   15–22/09/2010
James Cook tbc   Summer 2010

Follow the current research cruise (JC221) to PAP at EuroSITES outreach

Cruises to the JGOFS NABE

Cruise Principal Scientist Affiliation Start date
Discovery 175 P.R. Pugh IOS 18/06/1988
Discovery 181 R.T. Pollard IOS 18/04/1989
Atlantis 119/2 S. Honjo WHOI, USA 26/03/1989
Atlantis 119/4 J. Marra LDGO, USA 19/04/1989
Meteor 10/2 J. Lenz IFM, Kiel, Germany 05/05/1989
Discovery 182 M.J. Fasham IOS 08/05/1989
Atlantis 119/5 H. Ducklow WHOI, USA 18/05/1989
Discovery 183 R.P. Harris PML 11/06/1989
Discovery 184 I.N. McCave Cambridge University 23/07/1989
FRG     18/08/1989
Discovery 185 A.L. Rice IOS 18/08/1989
Tyro 1 H.J.W. de Baar NIOZ, Netherlands 22/08/1989
Discovery 190 A.J. Watson PML 22/04/1990
Discovery 191 M.V. Angel IOS 11/05/1990
Charles Darwin 53 G.B. Shimmield Edinburgh University 18/09/1990
Meteor 21/1 H. Thiel Hamburg University 16/03/1992
Meteor 21/3 J. Duinker IFM, Kiel, Germany 09/05/1992
Meteor 21/6 O. Pfannkuche GEOMAR, Kiel, Germany 26/07/1992
Meteor 26/1 K. Kremling IFM, Kiel, Germany 24/08/1993

There is a growing need for evermore accurate climatic models to predict future climate change and the impact this will have on human settlement, the insurance industry, fisheries, agriculture and nature at large.

Long term observations at fixed points in the open oceans are essential to provide high quality and high resolution data to increase our knowledge of how our oceans function, how they are changing and how this may impact on the climate.

Why was the Porcupine Abyssal Plain (PAP) chosen as a location?

The PAP site lies in the Northeast Atlantic ff the southwest coast of Ireland. There are several advantages to the PAP location which make it an ideal locality for an open ocean observatory.

  • A true open ocean site: It is as far as possible from the continental slope and the mid-Atlantic ridge reducing the effects of downslope sediment transport and the influence of the continental shelf.
  • Flat seabed: This facilitates a variety of types of benthic sampling  and reduces spatial heterogeneity.
  • Proximity to European ports despite being a remote abyssal location. This is advantageous for maintaining the mooring.
  • Low water column current speeds: This reduces the effects of advection.
  • CO2: This site displays a relatively high uptake of CO2 from the atmosphere which is relevant to issues of global climate change.