Abstract The search for a gas source near to Apache's Forties Field in the North Sea was motivated by the prediction of an ever-increasing fuel gas shortfall as the field oil rate declined. The Central North Sea is well known for a large number of shallow gas hazards in the Pleistocene section that have historically caused blowouts during exploration and development. These gas accumulations typically show up as small bright anomalies on seismic data. In 2009, a large gas anomaly was identified to the east of Forties, and the Aviat Field was discovered in 2010 when exploration well 22/7-5 was drilled. The Aviat Field reservoir is interpreted to be a subaqueous glacial outwash fan, consisting of silt-grade, rock flour material, deposited in front of a grounded ice sheet in some 400 m of water. Aviat sits on an overcompacted silty mudstone that was deformed by this ice sheet – the Crenulate Marker. The distribution of this horizon implies that the Early Pleistocene ice sheet covered at least the northern half of the UK North Sea. Although the Aviat reservoir is thin (2–9 m thick), the well tests, pressure profiles and geophysical response demonstrate that the reservoir is well connected, extensive (over 35 km 2 ) with high deliverability (up to 18 MMscfd achieved). Aviat was sanctioned in 2014 for development as a fuel gas supply for the Forties Field, with first gas achieved in July 2016.

Abstract The Forties Field, discovered by BP in 1970, is the largest oilfield on the UK Continental Shelf. It is trapped in a simple four-way dip closure, with a Paleocene turbidite sandstone reservoir. The Forties Field originally contained between 4.2 and 5 billion bbl of oil, with 2.75 billion bbl produced to June 2017. Production has been supported by water injection and the influx of a regional aquifer. The original development contained equally spaced producers with peripheral injectors. As the field matured, production was concentrated in the crestal parts of the field with injectors tending to be moved upflank. With the development of seismic lithology prediction and fluid detection, together with 4D seismic technology, it became possible in the late 1990s to target bypassed oil in unexpected locations throughout the field. In 2003, BP sold the field to Apache who were able to rejuvenate production, adding over 170 MMbbl oil reserves, with an extended drilling campaign targeting bypassed pay identified using seismic technologies. Production at the Forties facility has been further enhanced by the development of four satellite oilfields, Bacchus (Jurassic reservoir), Brimmond, Maule and Tonto (Eocene reservoirs), together with Aviat (Pleistocene reservoir) produced for fuel gas supply.

Abstract Hazardous effects of tephra fallout on Montserrat include roof collapse, aviation threats, health hazards from respirable crystalline silica, crop pollution, road safety and lahar generation. An advection-diffusion model was developed to investigate tephra dispersal from dome collapses and Vulcanian explosions, which generated most of the fallout tephra during the 1995–1999 eruptive period of Soufrière Hills Volcano. Wind field, atmospheric diffusion, gravity settling, aggregation and elutriation processes are considered. Computed isomass maps compare well with field observations and require aggregation of fine ash for good agreement. Probability maps were also compiled. Individual probability maps (for individual dome collapses and Vulcanian explosions) are based on the statistics of wind profiles and show that fallout tephra generated by individual eruptive events on a Montserrat scale do not cause serious damage in any area on Montserrat. Cumulative probability maps (for a given scenario of activity) are generated by sampling statistical distributions of wind profiles and eruptive events over an extended period of time. They show that persistent tephra fallout can accumulate enough material to cause roof collapses and serious damage to vegetation in the SW part of the island, and minor damage to vegetation in the north, as also confirmed by field data.

The field of volcanology has greatly changed during the last half century. The profession is now much more diverse and interdisciplinary, even including collaborating researchers from the social and medical sciences. This new mode of cooperation and working has been more successful in mitigating volcanic hazards and risks. There are fewer of the strong-willed lone rangers of the past and more of those who work with teams to more effectively understand how volcanoes work to protect those living on or near active or potentially active volcanoes. Moreover, there are more university departments with volcanology in their curricula and more international symposia and workshops focusing on mitigation of risk posed by volcano-related hazards. We all have respected colleagues and volcano observatories in many countries. The importance of understanding explosive volcanic eruptions and tracking of eruption plumes involves volcanologists, atmospheric physicists, and air-traffic controllers and is of great interest to the aviation industry. We now have the links in place between great science and practical applications.

Abstract During the period 1945-52, the geophysical industry underwent a tremendous expansion. (In fact, the 1952 peak would not be attained again for 30 years.) I do not have any clear recollection that I noticed this extraordinary growth. I apparently was so preoccupied with my continuing seismic R&D and the work on aviation medicine that Iwas not aware of the state of the industry until the good times had passed and we had begun one of our all-too-regular business downturns. But apparently others at Petty were sensitive to the highly competitive nature of the geophysical market, and they mandated an intensive research effort by the company. At least two results of this research had profound impact on the industry: J.0. Parr’s invention of weighted source and geophone arrays, and my conception of the common reflection point method. (The Patent Office was notoriously slow in processing applications at that time, and we did not receive patents for these ideas until the mid-50s – Parr’s in 1955 and mine in 1956.) The weighted arrays could be performed with contemporary equipment, so this idea was exploited immediately after the patent application was filed. Petty actively campaigned for the use of this technique throughout the decade. By contrast, the CRP method was just an interesting theory at that time because the technology needed for its implementation did not exist. Petty had 31 crews in the field in the summer of 1952, the company’s zenith in crew activity. There were 27 seismic crews (23 working in the US, two

Abstract By synthesizing relevant research findings from China and other countries, this paper discusses the distribution and eruption types of volcanoes in China. An analysis of the spreading characteristics of volcanic ash possibly caused by volcanic eruptions such as those from Changbaishan is presented, and the impact of volcanic ash on aviation flight safety, as well as several key methods of monitoring volcanic ash, are discussed. This paper also outlines the operational process of China's aviation industry in addressing volcanic ash and compares and analyses the handling of volcanic ash by civil aviation industries globally. Further, ways of dealing with volcanic ash are then suggested for China's aviation industry.