Magnitude 3.6 Earthquake off the coast of Massachusetts.

The United States Geological Survey recorded a Magnitude 3.6 Earthquake at a depth of 10 km off the south coast of Massachesetts, at about 9.10 am local time (about 2.10 pm GMT) on Sunday 8 November 2020. Events of this size are not usually dangerous, but are unusual in the eastern US, and people have reported feeling it across much of the northeasten United States and eastern Canada.

 

The approximate location of the 8 November 2020 Massachusetts Earthquake. USGS.

Earthquakes in New England are rare, which makes it hard to asses their precise origins, though most are thought to be associated with tectonic stresses in the Appalachian Mountains. The region is cross-cut from north-to-south by a number of ancient faults associated with the formation and breakup of the ancient supercontinent of Pangea, between 300 and 200 million years ago, though no sign of modern movement on these faults has been discovered. 

Witness accounts of quakes can help geologists to understand these events and the rock structures that cause them. If you felt this quake you can report it to the USGS here.

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Outbreak of Eastern Equine Encephalitis kills at least thirteen people in the United States.

At least thirteen people have died in an outbreak of Eastern Equine Encephalitis in the United States since August 2019. Outbreaks of the disease are expected in the US at this time of year, but this year's epidemic is exceptional both in terms of the number of cases reported and the number of fatalities. Five people have died in Michigan alone, out of a total of ten cases reported in the state, with three fatalities each in Massachusetts and Connecticut, and one each in Rhode Island and Indiana.  Only a single fatality was reported from the disease in 2018, out of 23 cases reported across the US, with 2 deaths in 2017 out of a total of 45 cases.

Eastern Equine Encephalitis is caused by the Eastern Equine Encephalitis Alphavirus, a form of Togavirus closely related to the Venezuelan Equine Encephalitis Alphavirus, and the Western Equine Encephalitis Alphavirus. These are single stranded positive-sense RNA Viruses. 

Colourised TEM micrograph of a mosquito salivary gland: The virus particles (virions) are coloured red. Fred Murphy and Sylvia Whitfield/Centers for Disease Control and Prevention/Public Health Image Library/Wikimedia Commons.

Eastern Equine Encephalitis is a Mosquito-born disease which primarily infects Birds, but is occasionally passed to Mammals through Mosquito bites. It gets the name 'Equine Encephalitis' because it is much more virulent in Horses than Humans, having first been discovered after an outbreak in Massachusetts killed 75 Horses in 1831. 

About 95% of people infected by the disease develop no symptoms, and are only detected if screening programs are introduced during an epidemic. Those who do develop symptoms suffer chills, fever, malaise, arthralgia, and myalgia for about two weeks, with about a quarter developing encephalitis (swelling of the brain), which can cause symptoms such as fever, headache, irritability, restlessness, drowsiness, anorexia, vomiting, diarrhea, cyanosis, convulsions, and coma. Around a third of patients that develop encephalitis die of the illness, with many others suffering permanent brain damage.

A vaccine against Eastern Equine Encephalitis is available for Horses, but none has been developed for Human use, nor is any specific treatment available, though fluid replacement, plus treatment with anticonvulsants (drugs to reduce convulsions) and antipyretics (drugs to reduce fever) have been shown to help.

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Humpback Whales seen off coast of Cornwall and in Boston Harbour.

Two Humpback Whales, Megaptera novaeangliae, have made local headlines this week, by entering waters popular with Humans on opposite sides of the Atlantic Ocean. The first was seen to in Boston Harbour, Massachusetts, on Saturday 3 August 2019, and has remained there for several days, feeding on fish and generally amazing Human users of the Harbour. Experts from the New England Aquarium Whale Watch team estimate that it is a male around 18 to 20 months old. Humpbacks were once common in Boston Harbour, but were almost wiped out by hunting in the early twentieth century. However, several have been seen feeding in the Harbour in the past decade, which the New England Aquarium report have all been young individuals that have not yet learnt to be cautious around Humans - Humpback Whales are no longer hunted commercially, but encounters with propeller driven boats can be painful and even dangerous to them.

A Humpback Whale in Boston Harbour on 6 August 2019. Boston Harbor Cruises.

The second Whale was spotted off the coast of Penzance in Cornwall, where it was feeding on Sand Eels. This Whale also seemed quite happy to approach tour boats in the area, suggesting that is is also unconcerned by Humans. As on the West Coast of America, Humpback Whales have been very rare in British waters for most of the past century, but sightings have become more common in the past decade, mostly off the west coast of Scotland, though sightings off Cornwall are also becoming more common.

A Humpback Whale off the coast of Cornwall this week. Hannah Jones/Marine Discovery Penzance/PA.

Humpback Whales were nearly exterminated by commercial Whaling in the first part of the twentieth century. The species has been protected since 1946, and in recent years their population has appeared to be recovering in many areas, now being seen as being of Least Concern  under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species. The Whales appear to be doing well in the Atlantic Ocean, with close encounters between Whales and Humans becoming more common.

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Large numbers of cold-stunned Sea Turtles wash up on beaches at Cape Cod, Massachusetts.

Over 400 Sea Turtles have washed up on beaches around Cape Cod, Massachusetts this week. Volunteers from the Massachusetts Audubon Society patrol the area at this time of year looking for distressed Turtles, but have been surprised by the high numbers found this week, which compare to about 600 found between October and December in recent years. A total of 173 Turtles have died as a result of hypothermia, many of them Kemp's Ridley Sea Turtle's, Lepidochelys kempii, a species considered to be Critically Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species. 

 Volunteers measuring rescued Turtles at the Massachusetts Audubon Society's Wellfleet Bay Wildlife Sanctuary. Massachusetts Audubon Society.

Ironically, though the Turtles are suffering as a result of the cold, the root cause of the problems is thought to be rising sea temperatures associated with global warming. Turtles breed in the warm waters of the Caribbean during the northern winter, and come northward during the summer to feed in the nutrient rich waters off the American east coast, however they have not, until fairly recently, come as far north Cape Cod, where they are apparently caught out by the sharp decline in water temperatures late in the year, resulting in the stranding of frozen animals seen this week.

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Leatherback Turtle dies in aquarium after being rescued from rope on Cape Cod, Massachusetts.

A 190 kg Leatherback Turtle, Dermochelys coriacea, has died at a Sea Turtle Hospital in Quincy,  Massachusetts, run by the New England Aquarium, the day after being found entangled in rope on Cape Cod on 31 October 2018. The female animal had been rescued from the rope and treated for an injury to its front flipper, but did not survive the night. It was later found to have swallowed a piece of plastic 28 cm in length and 12 cm in width, which is believed to be the cause of its death.

A female Leatherback Turtle being treated for injuries on 31 October 2018. New England Aquarium.

Leatherback Turtles are more-or-less global in distribution, being found in all the world's oceans except the Arctic and Southern, though this global population is generally considered to be split into a series of subpopulations. The species is currently considered to be Vulnerable under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species, as it has suffered a 40% loss in numbers over the past three generations, due to loss of breeding grounds and encounters with marine litter, particularly floating plastics, which they appear to be incapable of differentiating from Jellyfish, their main prey, and abandoned or lost fishing nets, in which they become entangled.

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Natural gas emissions in Boston, Massachusetts.

Methane (CH₄) is considered to be a serious atmospheric pollutant, both for its role as a greenhouse gas and its immediate effect on the area where it is released, where it can contribute to raised ozone levels at ground level, which is harmful to human health. It is currently calculated that methane is present in the atmosphere at levels 2.5 times as high as in the pre-industrial period, and that the level of atmospheric methane, which rose steadily till the mid 1980s, then slowed and levelled off by the early 2000s, has begun to rise sharply again since 2007. Methane emissions can come from a number of sources, including landfill sites and sewage treatment works, but the majority of the released methane is thought to come from leaks in the natural gas infrastructure (i.e. gas extracted from fossil hydrocarbon sources and intended for use as a domestic or industrial fuel). However the exact contribution of different sources to atmospheric pollution is unclear (and sometimes controversial), and current levels of atmospheric methane are much higher in many areas than predicted to arise from leaks in the gas distribution network.

In a paper published in the Proceedings of the National Academy ofSciences of the United States of America on 23 January 2015, a team of scientists led by KathrynMcKain of the School of Engineering and Applied Sciences and Department ofEarth and Planetary Sciences at Harvard University discuss the results of an experiment in which they monitored methane levels in and around the city of Boston, Massachusetts, for one year (twelve calendar months) in 2012-13, in order to determine levels of the gas in the city, and attempt to determine its origin.

McKain et al. monitored gas levels at four sites, Boston University and Copley Square in the city, and Harvard Forest and Nahant outside the urban area. Both the urban sites showed raised methane levels compared to the countryside year round, with the Boston University site with the Boston University site being 37.3 parts per billion above background in summer and 58.5 parts per billion above background in winter, while the Copley Square site produced levels 23.6 parts per billion above background in summer and 39.3 parts per billion above background in winter.

Location of two city [Boston University (BU), 29-m height; CopleySquare (COP), 215-m height] and two peripheral [Harvard Forest (HF);Nahant (NHT)] measurement stations (black points) in Boston, and the surrounding area, overlaid on a map of the number of housing units with NG per square kilometer (14). The 90-km radius circle delineates the ∼18,000km² land area for which CH4 emissions and the NG loss rate were calculated.The magenta and purple contours enclose 50% of the average footprint(sensitivity area) of the BU and COP afternoon measurements, respectively.The two city sites are difficult to distinguish at this scale because the horizontaldistance between them is ∼2 km. The influence area is ∼80% largerfor COP than BU because the former station is higher. McKain et al. (2015).

In order to determine the origin of the gas, McKain et al. also monitored ethane (C₂H₆) levels at each site. Ethane forms a significant proportion of supplied natural gas, but is not produced by microbial sources such as wetlands, landfill or sewage farms. Since Boston lacks other potential sources of atmospheric ethane, such as natural geological gas seeps or hydrocarbons refineries, this is taken as a good proxy for gas emitted by the natural gas infrastructure. Based upon this McKain et al. calculate that 98% of atmospheric methane in winter and 67% of atmospheric methane in winter originates from the natural gas infrastructure (a higher percentage in winter would be expected, as humans use less fuel and microbial production is higher).

This suggests that 2.7% of all natural gas supplied to the Boston area during the study period was leaked into the atmosphere. It is currently estimated that 0.7% of all supplied natural gas in the US is lost to the atmosphere, though this figure is not broken down by regions. The State ofMassachusetts produces its own figures, and estimates that 1.1% of supplied natural gas is lost (68% of the study area lies within Massachusetts, while 88% of the supplied gas in the state is consumed within the study area).

Reconstructed geographical distribution of NG consumption, in unitsof CH₄ mass flux, during September 2012 through August 2013 for the fourstates included in the study region. McKain et al. (2015).

McKainet al.’s figures suggest that both the US national figures and the independent figures produced in Massachusetts are severe underestimates. They suggest that this is because these figures are based upon detected leeks from the system (i.e. leeks large enough to be noticed and responded to), and that numerous smaller leeks could go undetected, particularly if occurring in inaccessible places. They also note that leeks on private property are not included in the official figures, but will still contribute to atmospheric pollution.

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Assessing the risks of cement casing failure at oil and gas wells in Pennsylvania.                 Like other areas of the US, Pennsylvania has seen an increase in oil and gas production in recent years, driven by the expanded targeting of shale gas deposits using hydraulic fracturing (blasting water and chemicals into shale beds at high pressure to break up the shale...

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Interpreting an Insect trace fossil from the Late Carboniferous of Massachusetts.

In a paper published in the Proceedings of the National Academy of Sciences of the United States of America in April 2011, Richard Knecht of the Department of Geology at Tufts University, Michael Engel of the Division of Entomology (Paleoentomology) at the Natural History Museum and the Department of Ecology and Evolutionary Biology at the University of Kansas and Jacob Benner also of the Department of Geology at Tufts University described an Insect trace fossil from the Late Carboniferous Wamsutta Formation of Massachusetts, which they interpret as a landing trace left by a Mayfly (Ephemeropterida) in soft mud in a marginal freshwater habitat.

(A) Lower-facing side preserving trace fossil in concave epirelief. Two ripple mark crests are evident in this view running from left to right across the bedding plane. (B) Upper-facing side (in convex hyporelief). Possible incipient mud cracks are visible to the left of the trace fossil. Knecht et al. (2011).

In a paper published in the journal Evolution in January 2013, James Marden of the Department of Biology at Pennsylvania State University presents an alternative view of the Wamsutta Formation specimen, suggesting that it might be a trace left by a surface-skimming Stonefly (Plecoptera).

Knecht et al. had suggested that the insect was a Mayfly due to the absence of antennae and presence of traces left by two terminal filaments, furthermore ruling out a Stonefly as this group was not present in the Carboniferous. However Marden observes that a Carboniferous Stonefly was recorded from China in a paper published in August 2011 (after the publication of the Knecht et al. paper), implying that the group had arisen by this time, and that this group actually has two terminal filaments (unlike the Mayflies, which have three) and tend to hold their antennae aloft, where they do not make traces. Furthermore he shows a strong correlation between the morphology of the trace fossil and that of the underside of a modern Stonefly.

Ventral morphology of an extant neopteran insect (Plecoptera, Taeniopteryx) and the trace fossil (scale bars: A 5 mm; B 10 mm). Highlighted are sternal sclerites of Taeniopteryx, which, with minimal changes in size (primarily width) and relative position, match the fossil. Poststernum 1, basisternum 3, and furcasternum 3 are clearly defined in the fossil. Marden (2013).

Unlike Mayflies, Stoneflies are Neopteran Insects, meaning they can fold their wings along their bodies rather than keeping them stuck out at the sides at all times. Marden's examination of the Wamsutta Formation specimen shows marks alongside the body, which he interprets as traces made by the folded wings.

Evidence for marks made by the edges of folded neopteran wings. (A) Ventral view of a live Taeniopteryx stonefly. Arrows show the fore and hind wing leading edges, which sit flush against the ground when thewings are folded. Inset shows close-up of the paired wing edges. (B) Wing edge marks (at arrowheads) beside the abdomen of the trace fossil. Scale bars: A 5 mm (inset 0.1 mm); B 10 mm. Marden (2013).

The trace fossil also shows a number of faint marks outside the apparent reach of the leg-span of the tracemaker. Marden interprets these as wing-marks made by a Stonefly skimming across water by flapping its wings, prior to coming ashore on saturated sediment. Modern Stoneflies, which tend to be indifferent fliers, are known to move in this way, and similar marks were made by a Taeniopteryx beaching on wet kaolinite clay under experimental conditions.

Comparison of striations distal to the legs in the trace fossil with location of wingtips of a surface skimming stonefly. Left: Interpretation requiring lateral movement of the entire body to leave striations beyond the reach of the meso- and metathoracic legs while also moving forward to leave the linear marks parallel to the abdomen (i.e., two contradictory paths). Right: Dorsal view of a Taeniopteryx Stonefly skimming on the surface of water or wet sediment. Tips of the fore and hind wings contact the surface at locations consistent with the distal lateral marks in the trace fossil. Marden (2013).

See also Metamorphic Insects from the Late Carboniferous of Germany and France, A Cnemidolestodean Insect from the Late Carboniferous of Ningxia Province, China and A fossil Insect from the Late Devonian of Belgium. 

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