Seismic blasting in the Greenland Sea

Transcription

1 Seismic blasting in the Greenland Sea This year the Norwegian seismic company TGS-NOPEC aims to conduct offshore seismic blasting 2 in the high Arctic of Northeastern Greenland. The proposed project will be a continuation of seismic blasting which has been conducted every summer since 2011; hence, this year s testing will be the fifth consecutive summer of testing in the same ecologically sensitive area. As before, the testing will take place adjacent to closed areas and overlaps with areas of concern 3 designated for the protection of narwhal, walrus and the critically endangered bowhead whale (Spitsbergen population). The area is also in close proximity to the Northeast Greenland National Park. Inside the testing area, icebergs and sea ice are ever-present; this remote and harsh environment is no place for oil & gas exploration and development. Marine seismic blasting takes place from a specialised vessel, often accompanied by support vessels. The seismic vessel tows an array of air guns which repeatedly, at short intervals, blasts loud low frequency sound waves through the water column into the seabed. Single or multiple long streamer(s) with hydrophones are towed behind the air guns, which record sound waves reflected by the various sediment formations below the seabed. These streamers can be several kilometres long. The operations can take place for weeks at a time, depending on the size of area designated for the survey. The data that is captured is used to locate oil and gas deposits. Depending on the type of seismic blasting carried out, the data will provide a multiple kilometres deep 2D or 3D image of the seabed and the ground beneath it. When sufficient data has been acquired and analysed, oil companies can begin exploratory drillings in areas showing potential for oil deposits. Even after oil production has begun, seismic blasting can continue in order to provide a fourth dimension (time) to the images of the oil & gas reserve. 4 Shell, BP, Chevron, ENI, DONG, Statoil, ConocoPhillips, GreenPex and NUNAOIL are all owners of exploration and exploitation licenses in the seismic area in question. 1 This briefing does not cover the affects of noise to marine mammals and wildlife, please consult A Review of the Impact of Seismic Survey Noise on Narwhal & other Arctic Cetaceans. 2 Also known as seismic testing, seismic survey and seismic acquisition. 3 Appointed by the Greenlandic Government. 4 The continuation of seismic blasting will add to the noise generated from drill ships, rigs, platforms and vessels operating in the area.

2 Ice and freeze temperatures in the High Arctic The seismic survey will take place in the high Arctic 5, between approximately 75 N & 80 N and 13 W and 2 W. Areas this far north of the Arctic Circle see 24 hours of daylight in the summer months and a period of continuous darkness in the winter. The area is adjacent to the North East Greenland National Park which includes the Greenlandic sea territory of three nm from the baseline. Temperatures can be as low as -30 C in winter months, with summer temperatures peaking just above freezing (TGS-NOPEC 2015, 17). Ice is present in the area throughout the year, and the Northern part of the survey area might be ice covered at the beginning and end of the timeframe. 6 5 The high Arctic climate zone is the area where average July temperatures do not exceed 5 C. The area where average July temperatures do not exceed 10 C and don t drop below 5 C is the low Arctic climate zone. 6 Monthly mean ice concentration in Greenland from 2000 to entration.pdf

3 Two types of sea ice occur in the area; fast ice (stable and anchored to the shore) and drift or pack ice (moves around). The fast ice on the coast usually melts in the summer. However, in a few places a permanent ice cover is present (e.g. the Carlsberg Fjord) throughout the year. The drift ice is usually very dense and difficult to navigate except for during August and September (DCE 2011). In general, ice-free periods in high-arctic areas around Northeast Greenland extend for two to three months (DCE 2011, 39). In addition to sea ice, many icebergs originate from calving glaciers in the area. Icebergs differ from sea ice in various respects. Of particular importance when it comes to hydrocarbon exploration and exploitation, is the deep-draft and significant height of icebergs and the intense, local hazard they present. The icebergs can often be more than 50 m in height and several kilometres wide. Some of the icebergs originating from 79- Fjorden Glacier and Zachariae Glacier, have been described as being more like Arctic Ocean ice islands (DCE 2009). Throughout the survey window, drift ice and icebergs will be present in a southward drift due to the cold East Greenland Current. Ice in the area has proved challenging for TGS-NOPEC previous years. In 2015 TGS- NOPEC applied for 10,000 km lines of survey but expect to conduct 7,000 km. In previous years, similar maximum values were planned but the success was limited by sea ice conditions (TGS-NOPEC 2015). 1,812km of 2D seismic data was collected in 2011, 3,550km in 2012, 6,355km in 2013 and 5,528km in Whilst research predicts a continued climate warming and shows an overall trend over several decades of negative change to sea ice area and volume across the Arctic as a whole (despite year to year variations), the timing and rate of change is not uniform across the circumpolar Arctic. According to one study, the eastern side of the Greenland Sea has experienced recent warming, whereas the western side is still dominated by cold water brought down by the East Greenland Current (DCE 2011, 175). The summer ice 7 in the Greenland Sea has expanded 12 days per decade since 1979, whereas the neighbouring Barents Sea has expanded 20 days (Laidre, Kirstin L. et al. 2015). Seismic air guns poses a danger to marine life When TGS-NOPEC operates with 16 air guns (3,350 cubic inch air gun array) the expected peak volume will be between 259 db in water (re. 1 μpa at 1 m - peak to peak) and 229 db (RMS90% re. 1 μpa at 1 m) depending on the applied method. In air, 259 db is equivalent to db. 8 7 Time frame between spring and autumn sea ice transition dates. 8 University of Rhode Island

4 The noise levels from the seismic blasting would be perceived - by a human - as approx. eight times louder than a jet engine heard 50 m away (140 db) and approx. 64 times louder than a gunshot heard one m away (130 db). 9 The human threshold of pain is 125 db and eardrum rupture could happen around db. Physical and behavioural effects on marine mammals from noise are well documented; seismic blasting can be lethal or cause physical injury to marine mammals at close range. Animals further away from a seismic air gun can undergo behavioural changes such as interrupted migration, feeding and breeding. Walruses, narwhals, blue whales and bowhead whales are especially at risk in the area (DCE 2011, 192). Of particular concern is the fact that the seismic surveys take place adjacent to a Closed Area put in place to protect narwhals and walruses, and overlaps with Area of Concern designated due to the concern of bowhead whales as well as narwhals and walruses. This year no seismic blasting will take place inside closed areas as has happened in previous years, but the space between the planned lines has been reduced considerably. TGS-NOPEC will apply a 200m Injury Zone where seismic output will be reduced to a single mitigation gun if a marine mammal is observed in the area (TGS-NOPEC 2015, 86). Arctic waters can have strongly stratified water columns and as such it cannot be assumed that there is a simple relationship between sound pressure levels and distance to source. Acoustic tags attached to sperm whales recorded high sound pressure levels (160 db re. 1 μpa peak to peak) more than 10 km away from the seismic vessel (DCE 2011, 183). As such, even though the seismic blasting takes place outside closed areas, the sound will still travel and can cause disturbance. Underwater noise is considered a marine pollutant by the United Nations Convention on the Law of the Sea. The convention includes energy to define pollution of the marine environment. 10 The European Union also considers underwater noise as a marine pollutant. The Marine Strategy Framework Directive defines pollution as the direct or indirect introduction into the marine environment, as a result of human activity, of substances or energy, including human-induced marine underwater noise, 11 For a full account of the threats and impacts on whales from seismic blasting please consult A Review of the Impact of Seismic Survey Noise on Narwhal & other Arctic Cetaceans. 9 The calculation behind the comparison is different since the nature of the noise from a jet engine (more constant) varies from the nature of the noise from a seismic blast (abrupt and more similar to a gunshot). Georgia State University and 10 Article

5 The companies behind the seismic blasting Northeast Greenland has been of interest to the oil industry for several decades but no exploratory drilling has yet been attempted in this remote and harsh region. In 1989 the KANUMAS consortium 12 was awarded a prospecting license and acquired 2D seismic data in 1992, 1994 and Today, five exploration and exploitation licenses are valid in the Greenland Sea and were awarded in and 2014: Avinngaq (2,548 km 2 ) with Statoil as operator and ConocoPhillips and NUNAOIL 14 as partners. Amaroq (2,630 km 2 ) with ENI as operator and BP, DONG and NUNAOIL as partners. Umimmak (2,220 km 2 ) with Chevron as operator and GreenPex, Shell and NUNAOIL as partners. Nerleq (2,634 km 2 ) with Chevron as operator and GreenPex, Shell and NUNAOIL as partners. Qialivaq (2,260 km 2 ) with ENI as operator and BP and NUNAOIL as partners. 15 None of the companies above have yet revealed any date as to when they would initiate exploration drilling in the Greenland Sea. However, in an interview with Roy Leadholm, a ConocoPhillips executive and head of GOIA, they suggested that drilling in Northeast Greenland will not take place earlier than 2025 (McGwin 2015). Mr. Roy Leadholm also confirmed in the interview that license holders in Greenland are actively analysing seismic data in preparation for future drilling: By reprocessing the data, companies aim to significantly enhance the geological images, on which future decisions if and how to proceed will depend. According to TGS-NOPEC the data obtained in 2014 was made available to clients in Q (TGS-NOPEC 2014). According to the 2014 Annual Report from NUNAOIL, the consortiums involved in Northeast Greenland are currently focusing on acquiring seismic and geological data together with information on oceanographic, meteorological, environmental, and ice conditions. 12 BP, Exxon, Chevron, JOGMEC, Shell, Statoil and NUNAOIL. The KANUMAS term is no longer used NUNAOIL is a silent partner in all the licenses and those not carry expenses or share risks. 15 Awarded in 2014.

6 Shell The Anglo-Dutch company owns the largest share of the Umimmak and Nerleq licenses together with GreenPex and the operator Chevron. Each of the oil companies owns 29,17 pct of each license block. Statoil The Norwegian stateowned company Statoil is the operator of the Avinngaq licenses with total ownership of 52.5 pct.

7 Unlike Greenland, oil drilling in ice-filled waters is not allowed in Norway. The definition used in Norway is areas where there is a 30 percent chance of sea ice in April based on 30 years of historical ice data. 16 Compared to other Arctic coastal nations this is fairly strong policy, however, the Norwegian Polar Institute suggest a definition with a 0 pct. chance of sea ice. Despite the differences between 0 and 30 pct. chance, this policy is important to keep in mind when other Arctic coastal states claim to be following highest safety and environmental standards, best availble practices or even Norwegian standards when it comes to arctic drilling. ENI The Italian oil company is the operator of the Qialivaq license with a total ownership of 43,75 pct. and the Amaroq license with a total ownership of 35 pct. DONG ENERGY The Danish state owned company DONG owns a 17.5 pct. of the Amaroq license and (map).

8 Sources DCE (2011), The Western Greenland Sea. A strategic environmental impact assessment of hydrocarbon activities, Danish Centre for Environment and Energy, DCE (2009), The Western Greenland Sea. A preliminary strategic environmental impact assessment of hydrocarbon activities in the KANUMAS East area. Danish Centre for Environment and Energy, 2009, Laidre, Kristin L. et al. (2015), Arctic marine mammal population status, sea ice habitat loss, and conservation recommendations for the 21st century, in Conservation Biology, Vol. 29 Issue 3, p , June 2015 McGwin, Kevin (2015), Oli firms in Greenland: we re still here, in Arctic Journal, 22. maj 2015, TGS-NOPEC (2015), Environmental Impact Assessment North East Greenland v1, March 2015, 20seismiske%20data/Documents/TGS%20EIA%20NEG15%20eng.pdf TGS-NOPEC (2014), TGS announces new multi-year, multi-client project Northeast Greenland, press release June 25th 2014, Contact Greenpeace Nordic Njalsgade 21G, 2 DK-2300 Copenhagen Sune Scheller sun.scheller@greenpeace.org

9 Technical appendix: TGS- NOPEC s 2015 operation The Government of Greenland has granted TGS-NOPEC permission to conduct the 2D seismic blasting from August 4th to October 31st 2015 (inclusively). 17 The seismic vessel M/V Akademik Shatskiy is owned by Sevmorneftegeofizika and operated by TGS-NOPEC. The Akademik Shatskiy will tow a single array of 16 (2x8) air guns (total active volume of 3,350 cubic inches) around 250 behind the vessel at approx. 7-9 m depth. A backup array of 1,675 cubic inches is theoretically available. The streamer with hydrophones will be a maximum of m long (potentially shorter in ice) towed at 12 m depth. The 16 air guns will blast loud, low frequency sound waves down through the water column and into the seabed every 10 seconds, 24 hours a day while operating at a cruise speed of approx. 5 knots. TGS-NOPEC has applied to shoot a total of 10,000 km this summer but at a public information meeting the company estimated a total of 7,000 km lines. 18 The operation will map out the seabed from 500 to 10,000m below seabed and as such is to be considered a relative deep seismic imaging. TGS-NOPEC models shows an expected peak-to-peak volume of 259 db re. 1 μpa at 1 m distance and a zero-to-peak volume of 253 db re. μpa at 1 m when operating with 3350 cubic inch air gun array If TGS-NOPEC decides to implement the extra backup array of 1,675 cubic inches the sound level will be 264 db re. 1 μpa at 1 m distance and a zero-to-peak volume of 258 db re. μpa at 1 m (TGS-NOPEC 2015, 54). TGS-NOPEC will apply a 2km mitigation zone for bowhead whales and 500m for other marine mammals. Further, the seismic blasting will not take place closer than 2,5km to any closed area for walrus. 17 Letter of approval from Greenlandic authorities 18 Nuuk, Greenland, May 25th 2015

10 TGS- NOPEC fleet Seismic vessel M/V Akademik Shatskiy Owned by the Russian geophysical company Sevmorneftegeofizika. The vessel will be operated by TGS- NOPEC. Icebreaker Otso Owned by the Finish state owned shipping company Arctia Shipping. In April 2015 the Otso was announced chartered on a two year contract with the option of additional two years to assist a seismic company. Based on the contract the Otso has been in dock in order to receive extensive modification preparing the vessel for Arctic operations. 19 The main purpose of the icebreaker is to move ice away from the survey vessel with different techniques: bump and flush, crush and flush, and cut and flush. This will allow the survey vessel to continue acquisition in waters 70-90% covered by ice. In pressurised ice seismic acquisition can be undertaken in waters up to around 60% density. 19

11 Supply vessel M/V Bjørkhaug Owned by the Norwegian Maritim Management Group