Author: Staff Reporter

A hidden tectonic fault in Canada’s Yukon, previously deemed inactive, may soon produce a major earthquake of at least magnitude 7.5, according to new research.

An extensive fault line known as the Tintina fault, stretching from northeastern British Columbia to central Alaska, has quietly accumulated strain over at least the last 12,000 years. Recent studies have revealed that this fault remains significantly active, challenging previous perceptions of its dormancy.

Researchers caution that predicting when the next significant earthquake will occur is impossible, but evidence suggests it is inevitable. Dr. Theron Finley, the lead author of the study published in Geophysical Research Letters, indicated to BBC Science Focus that their findings point to an active fault which continues to build up strain over time. “And so we anticipate that in the future, it will rupture again,” Finley said.

The Tintina fault is a classic example of a ‘right-lateral strike-slip fault’—a type of fault where two blocks of the Earth’s crust slide past each other horizontally. During an earthquake, if the opposite side of such a fault moves to the right, it exemplifies this right-lateral motion.

Historically, one side of the fault has shifted approximately 430 kilometers (around 270 miles), predominantly during the Eocene epoch, which occurred roughly 56 to 33.9 million years ago. During that era, it shifted at a rate of about 13 mm (0.5 inches) per year. Despite a few minor earthquakes ranging from magnitude three to four in the area, the Tintina fault was long thought dormant until recent technologies provided fresh insights.

Utilizing satellite surface models and drone-mounted Light Detection and Ranging (LIDAR), Finley’s team re-examined the fault, penetrating the dense forest to reveal traces of a seismically active past and what could be a similarly active future for the Yukon region.

Scattered fault scarps, which are narrow landforms formed when quakes rupture to the surface, were found across the landscape. While these scarps can extend for tens to hundreds of kilometers, they typically measure only a few meters in height and width. “In the case of the Tintina fault, the scarps appear as an interesting series of aligned mounds,” Dr. Finley noted.

Dating these features allowed researchers to discover that while the fault has experienced multiple ruptures over the past 2.6 million years, it has not produced a major earthquake in recent history, specifically the last 12,000 years. During this time, it has been accumulating strain at a pace of 0.2 to 0.8 mm (0.008 to 0.03 inches) annually.

Fortunately, the potentially affected area is sparsely populated. However, Finley warns that when the fault does eventually rupture, it could result in significant landslides, infrastructure damage, and adverse effects on nearby communities.

“I want to be clear that we don’t have a great sense of how imminent an earthquake is,” Finley emphasized. He stated that although a substantial period may have passed since the last major event, it remains unclear whether another is likely to occur imminently or far into the future.

With the fault now confirmed as active, the next research goal is to better estimate the frequency of large earthquakes at this site. While this won’t predict exact timings, it could provide a more reliable timeframe within which another large earthquake may be expected. “Earthquakes don’t necessarily occur periodically,” Finley stated, “but it would give us a better sense of how often we expect large earthquakes.” Nonetheless, any future activity on the Tintina fault is likely to result in a significant event.

Scientists have discovered a new organism off the Japanese coast that challenges traditional definitions of life, straddling the line between cellular organisms and viruses.

Ryo Harada and his team at Dalhousie University have identified an unusual organism named Sukunaarchaeum mirabile, found in DNA taken from a plankton species off the coast of Japan. This discovery is prompting scientists to reconsider what qualifies as a living organism, given that Sukunaarchaeum exhibits characteristics of both cellular life forms and viruses.

Traditionally, organisms have been defined by their ability to grow, produce energy, and reproduce independently. However, this simple definition does not accommodate viruses, which can only replicate within a host organism and remain inactive outside it. Sukunaarchaeum, while undeniably cellular, borrows several viral traits, complicating the clear-cut distinctions long relied upon in biology.

This discovery shakes up existing definitions by showing that Sukunaarchaeum, despite having the cellular components necessary for making ribosomes and messenger RNA, depends heavily on its host for nearly all other functions. Its genome is remarkably small, encapsulating only 238,000 base pairs, which is substantially smaller than the previous record holder, Nanoarchaeum equitans, which has about 490,000 base pairs.

The researchers describe Sukunaarchaeum as a “cellular entity retaining only its replicative core,” lacking almost all recognizable metabolic pathways. Its genome, characterized by elements typically found in viruses rather than in fully autonomous microbes, includes instructions only for basic replication, transcription, and translation activities.

Sukunaarchaeum resides within the domain Archaea, one of the three principal domains of life, and doesn’t belong to the virus group. Detailed phylogenetic analysis positions it on a distinct and distant branch within the Archaea domain, suggesting the possibility of a new phylum specifically for this organism.

The organism was discovered unexpectedly while sequencing DNA from the dinoflagellate Citharistes regius. Researchers identified a string of foreign DNA that bore no resemblance to any previously catalogued species. Sukunaarchaeum seems to rely heavily on its host, similar to some other plankton that depend on bacterial or algal partners for essential functions.

These findings suggest that traditional views of life as a binary concept may need revision. Some scientists argue that life should be understood as a spectrum, which Sukunaarchaeum pushes into the spotlight. The discovery brings to light the possibility that many more such lineages might exist, previously dismissed in environmental sequence data as mere contaminants or viral anomalies.

The definition of “alive” carries significant implications, influencing funding, public health, and even planetary protection measures for space exploration. If other organisms like Sukunaarchaeum are found, biosecurity measures that only target free-living microbes could overlook significant classes of symbiotic parasites.

Researchers view this organism as potentially valuable in synthetic biology, offering insights into the minimal genetic load necessary for cellular function. Harada and his team speculate that the extreme streamlining of Sukunaarchaeum’s genome could result from a host environment that provides guaranteed nutrients, making some biological pathways obsolete over time.

Some paleobiologists suggest that such extreme genome reduction might provide a glimpse into early evolutionary history, when cells likely shared genes and resources more liberally. If this is true, today’s viruses and streamlined symbionts might come from an ancient lifestyle rather than being biological outliers.

Ongoing research aims to determine whether similar organisms exist in other marine ecosystems or symbiotic relationships, possibly through re-analyzing existing metagenomic databases for overlooked sequences resembling Sukunaarchaeum. Another objective is identifying the specific host organism that supports Sukunaarchaeum’s survival, which remains undiscovered.

Researchers have uncovered the bacterial cause behind a decade-long epidemic that has decimated over 5 billion sea stars along the Pacific coast of North America.

Scientists have finally identified the cause of an epidemic that has led to the deaths of more than 5 billion sea stars off the Pacific coast from Mexico to Alaska over the past decade. Known as sea star wasting disease, the condition has devastated more than 20 species since 2013 and is still ongoing. The sunflower sea star has been the hardest hit, with an estimated 90% population loss during the first five years of the outbreak.

Sea stars, commonly referred to as starfish, generally have five arms, though some species may have up to 24. These marine animals display a wide array of colors, ranging from solid orange to combinations of orange, purple, brown, and green. Initially, the cause of the mass die-off was a mystery, but recent research points to bacteria as the culprit.

Marine disease ecologist Alyssa Gehman from the Hakai Institute in British Columbia, Canada, who played a role in determining the cause, described the effects of the disease as “gruesome.” Infected sea stars develop lesions, and their arms eventually detach.

A study published in Nature Ecology and Evolution has identified the bacteria Vibrio pectenicida as responsible for the disease. This finding resolves an enduring mystery concerning the severe marine ailment, according to Rebecca Vega Thurber, a marine microbiologist at the University of California, Santa Barbara, who was not involved in the study.

The search for the cause took over a decade, involving several missteps and complexities. For years, researchers suspected a virus might be responsible, particularly a densovirus. However, this virus was later found to be a normal component of healthy sea stars, not linked to the disease, said Melanie Prentice, a co-author of the study from the Hakai Institute.

Other research efforts failed to identify the true cause because they focused on tissue samples from dead sea stars, which lacked the coelomic fluid—an organ-surrounding bodily fluid—where the bacteria were discovered. The new study, with its detailed analysis of this fluid, was instrumental in identifying the bacteria as the cause.

Blake Ushijima, a microbiologist from the University of North Carolina, Wilmington, not involved in the study, acknowledged the challenges in tracing the root cause of underwater environmental diseases. He described the research team’s approach as “really smart and significant.”

With the bacterial cause identified, scientists can now develop strategies to help sea star populations. Melanie Prentice suggested testing the health of remaining sea stars and considering options such as relocation or breeding in captivity for future reintroduction. Additionally, researchers may explore whether some populations possess natural immunity and whether treatments like probiotics could enhance immunity against the disease.

The discovery offers a renewed sense of hope for sea star conservation and a chance to mitigate the impacts of this devastating epidemic in the ocean ecosystem.