ALBERT

Description: Marine heatwaves (MHWs) are prolonged extreme oceanic warm water events, that can cause substantial and sometimes devastating impacts on marine ecosystems. Our knowledge of regional and remote drivers, teleconnections, and local-scale processes underpinning large-scale and iconic MHWs has improved significantly over the past decade because of focused research efforts around the world. Dynamical knowledge of MHW drivers, including those from remote sources such as modes of climate variability and their teleconnections, coupled with local MHW amplification or decay processes, is critical to the process-based understanding of MHW predictability. However, the key development needed for effective adaptation and mitigation efforts by marine conservation and fisheries managers is better MHW prediction skill. MHW predictability depends on multiple factors including how we define MHWs, the regions in which they occur – e.g., coastal versus offshore, western boundary versus eastern boundary regions –, the spatial and temporal scales of the events, atmospheric heat flux versus ocean advection-driven events, and driver persistence. This presentation will explore MHW predictability on various timescales, focusing on the physical processes that offer a prediction. Some significant MHW events around Australia will be central to this discussion.

Description: The protracted nature of the 2016-2017 central Italy seismic sequence, with multiple damaging earthquakes spaced over months, presented serious challenges for the duty seismologists and emergency managers as they assimilated the growing sequence to advise the local population. Uncertainty concerning where and when it was safe to occupy vulnerable structures highlighted the need for timely delivery of scientifically based understanding of the evolving hazard and risk. Seismic hazard assessment during complex sequences depends critically on up-to-date earthquake catalogues-i.e., data on locations, magnitudes, and activity of earthquakes-to characterize the ongoing seismicity and fuel earthquake forecasting models. Here we document six earthquake catalogues of this sequence that were developed using a variety of methods. The catalogues possess different levels of resolution and completeness resulting from progressive enhancements in the data availability, detection sensitivity, and hypocentral location accuracy. The catalogues range from real-time to advanced machine-learning procedures and highlight both the promises as well as the challenges of implementing advanced workflows in an operational environment.

Description: Published

Description: 710

Description: 4T. Sismicità dell'Italia

Description: JCR Journal

Description: 〈jats:title〉Abstract〈/jats:title〉 〈jats:p〉—J. BLUNDEN, T. BOYER, AND E. BARTOW-GILLIES〈/jats:p〉 〈jats:p〉Earth’s global climate system is vast, complex, and intricately interrelated. Many areas are influenced by global-scale phenomena, including the “triple dip” La Niña conditions that prevailed in the eastern Pacific Ocean nearly continuously from mid-2020 through all of 2022; by regional phenomena such as the positive winter and summer North Atlantic Oscillation that impacted weather in parts the Northern Hemisphere and the negative Indian Ocean dipole that impacted weather in parts of the Southern Hemisphere; and by more localized systems such as high-pressure heat domes that caused extreme heat in different areas of the world. Underlying all these natural short-term variabilities are long-term climate trends due to continuous increases since the beginning of the Industrial Revolution in the atmospheric concentrations of Earth’s major greenhouse gases.〈/jats:p〉 〈jats:p〉In 2022, the annual global average carbon dioxide concentration in the atmosphere rose to 417.1±0.1 ppm, which is 50% greater than the pre-industrial level. Global mean tropospheric methane abundance was 165% higher than its pre-industrial level, and nitrous oxide was 24% higher. All three gases set new record-high atmospheric concentration levels in 2022.〈/jats:p〉 〈jats:p〉Sea-surface temperature patterns in the tropical Pacific characteristic of La Niña and attendant atmospheric patterns tend to mitigate atmospheric heat gain at the global scale, but the annual global surface temperature across land and oceans was still among the six highest in records dating as far back as the mid-1800s. It was the warmest La Niña year on record. Many areas observed record or near-record heat. Europe as a whole observed its second-warmest year on record, with sixteen individual countries observing record warmth at the national scale. Records were shattered across the continent during the summer months as heatwaves plagued the region. On 18 July, 104 stations in France broke their all-time records. One day later, England recorded a temperature of 40°C for the first time ever. China experienced its second-warmest year and warmest summer on record. In the Southern Hemisphere, the average temperature across New Zealand reached a record high for the second year in a row. While Australia’s annual temperature was slightly below the 1991–2020 average, Onslow Airport in Western Australia reached 50.7°C on 13 January, equaling Australia's highest temperature on record.〈/jats:p〉 〈jats:p〉While fewer in number and locations than record-high temperatures, record cold was also observed during the year. Southern Africa had its coldest August on record, with minimum temperatures as much as 5°C below normal over Angola, western Zambia, and northern Namibia. Cold outbreaks in the first half of December led to many record-low daily minimum temperature records in eastern Australia.〈/jats:p〉 〈jats:p〉The effects of rising temperatures and extreme heat were apparent across the Northern Hemisphere, where snow-cover extent by June 2022 was the third smallest in the 56-year record, and the seasonal duration of lake ice cover was the fourth shortest since 1980. More frequent and intense heatwaves contributed to the second-greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Glaciers in the Swiss Alps lost a record 6% of their volume. In South America, the combination of drought and heat left many central Andean glaciers snow free by mid-summer in early 2022; glacial ice has a much lower albedo than snow, leading to accelerated heating of the glacier. Across the global cryosphere, permafrost temperatures continued to reach record highs at many high-latitude and mountain locations.〈/jats:p〉 〈jats:p〉In the high northern latitudes, the annual surface-air temperature across the Arctic was the fifth highest in the 123-year record. The seasonal Arctic minimum sea-ice extent, typically reached in September, was the 11th-smallest in the 43-year record; however, the amount of multiyear ice—ice that survives at least one summer melt season—remaining in the Arctic continued to decline. Since 2012, the Arctic has been nearly devoid of ice more than four years old.〈/jats:p〉 〈jats:p〉In Antarctica, an unusually large amount of snow and ice fell over the continent in 2022 due to several landfalling atmospheric rivers, which contributed to the highest annual surface mass balance, 15% to 16% above the 1991–2020 normal, since the start of two reanalyses records dating to 1980. It was the second-warmest year on record for all five of the long-term staffed weather stations on the Antarctic Peninsula. In East Antarctica, a heatwave event led to a new all-time record-high temperature of −9.4°C—44°C above the March average—on 18 March at Dome C. This was followed by the collapse of the critically unstable Conger Ice Shelf. More than 100 daily low sea-ice extent and sea-ice area records were set in 2022, including two new all-time annual record lows in net sea-ice extent and area in February.〈/jats:p〉 〈jats:p〉Across the world’s oceans, global mean sea level was record high for the 11th consecutive year, reaching 101.2 mm above the 1993 average when satellite altimetry measurements began, an increase of 3.3±0.7 over 2021. Globally-averaged ocean heat content was also record high in 2022, while the global sea-surface temperature was the sixth highest on record, equal with 2018. Approximately 58% of the ocean surface experienced at least one marine heatwave in 2022. In the Bay of Plenty, New Zealand’s longest continuous marine heatwave was recorded.〈/jats:p〉 〈jats:p〉A total of 85 named tropical storms were observed during the Northern and Southern Hemisphere storm seasons, close to the 1991–2020 average of 87. There were three Category 5 tropical cyclones across the globe—two in the western North Pacific and one in the North Atlantic. This was the fewest Category 5 storms globally since 2017. Globally, the accumulated cyclone energy was the lowest since reliable records began in 1981. Regardless, some storms caused massive damage. In the North Atlantic, Hurricane Fiona became the most intense and most destructive tropical or post-tropical cyclone in Atlantic Canada’s history, while major Hurricane Ian killed more than 100 people and became the third costliest disaster in the United States, causing damage estimated at $113 billion U.S. dollars. In the South Indian Ocean, Tropical Cyclone Batsirai dropped 2044 mm of rain at Commerson Crater in Réunion. The storm also impacted Madagascar, where 121 fatalities were reported.〈/jats:p〉 〈jats:p〉As is typical, some areas around the world were notably dry in 2022 and some were notably wet. In August, record high areas of land across the globe (6.2%) were experiencing extreme drought. Overall, 29% of land experienced moderate or worse categories of drought during the year. The largest drought footprint in the contiguous United States since 2012 (63%) was observed in late October. The record-breaking megadrought of central Chile continued in its 13th consecutive year, and 80-year record-low river levels in northern Argentina and Paraguay disrupted fluvial transport. In China, the Yangtze River reached record-low values. Much of equatorial eastern Africa had five consecutive below-normal rainy seasons by the end of 2022, with some areas receiving record-low precipitation totals for the year. This ongoing 2.5-year drought is the most extensive and persistent drought event in decades, and led to crop failure, millions of livestock deaths, water scarcity, and inflated prices for staple food items.〈/jats:p〉 〈jats:p〉In South Asia, Pakistan received around three times its normal volume of monsoon precipitation in August, with some regions receiving up to eight times their expected monthly totals. Resulting floods affected over 30 million people, caused over 1700 fatalities, led to major crop and property losses, and was recorded as one of the world’s costliest natural disasters of all time. Near Rio de Janeiro, Brazil, Petrópolis received 530 mm in 24 hours on 15 February, about 2.5 times the monthly February average, leading to the worst disaster in the city since 1931 with over 230 fatalities.〈/jats:p〉 〈jats:p〉On 14–15 January, the Hunga Tonga-Hunga Ha'apai submarine volcano in the South Pacific erupted multiple times. The injection of water into the atmosphere was unprecedented in both magnitude—far exceeding any previous values in the 17-year satellite record—and altitude as it penetrated into the mesosphere. The amount of water injected into the stratosphere is estimated to be 146±5 Terragrams, or ∼10% of the total amount in the stratosphere. It may take several years for the water plume to dissipate, and it is currently unknown whether this eruption will have any long-term climate effect.〈/jats:p〉

Description: Abstract

Description: The three datasets presented here are high-resolution catalogs containing origin time of seismic events for the same region and time range that have derived using AI-based techniques and a matched filter search. The corresponding standard catalogs from the agencies AFAD and KOERI are available under https://tdvms.afad.gov.tr/ (last accessed 28/07/2022) and http://www.koeri.boun.edu.tr/sismo/2/earthquake-catalog/ (last accessed 28/07/2022), respectively, when searching in the bulletin for longitude 28.80-29.10, latitude 40.4-40.625, and from November 1st 2018 to January 31th, 2019. Specifications for the three catalogs are. (i) Catalog derived utilizing AI-based techniques. We applied the PhaseNet deep learning method (Zhu & Beroza, 2019) to detect and pick the P-and S- waves of seismic events embedded in continuous seismic recordings from 16 stations surrounding the region of interest resampled at 100 Hz. The method was trained on a dataset from Northern California, but has been shown to generalize well to other tectonic settings. The picks were associated into seismic events using the GaMMA association method (Zhu et al., 2022). Manual check of the waveforms from all detections led to 516 seismic events with clear waveforms retained for further processing. (ii) Template matching catalog A. We applied the matched filter algorithm EQcorrscan (Chamberlain et al., 2017) to the two nearby seismic stations with the largest data recovery during the period of interest, ARMT and MDNY. We utilized 14 manually picked template events with M 〉 2 that occurred in the region of interest during the analyzed time period, which were recorded in both stations. As a first criteria to remove false detections, we retained only detections exhibiting a Median Absolute Deviation (MAD) larger than eight. We required detections from different templates to be at least 1.5 seconds apart. To remove duplicate detections (e.g., detections of the same event by different templates), we retained the detections with the highest average correlation if multiple detections occurred within 2.5 seconds. As a second criteria, we calculated cross-correlation derived phase-picks. A pick was declared if the maximum normalized correlation between the signal of the template event and of the detection exceeds 0.7. We correlated the signals in a short window of ±0.3 seconds around the assumed pick time based on a time-shifted version of the template phase-pick. We retained the S-pick exhibiting the higher cross-correlation value with respect to the template. Following this step, we considered only detections with ≥ 2 picks. In case of events with only two picks we ensured that that were from the same station to have control on the ts-tp and therefore the distance of the event from the detecting station. This catalog contains 2,462 seismic events (all manually reviewed) with magnitudes MW in the range [-2.4, 4.5]. Since we were not able to locate the events from this catalog, we considered as “origin time” the time of the first arrival. (iii) Template matching catalog B. We derived a second template matching catalog utilizing twelve of the closest seismic stations displaying high seismic data recovery during the analyzed time period. An initial list of detections was generated following the same steps as for the Template Matching Catalog A, with the additional requirement that all detections must contain at least one picks from one of the two closest stations, ARMT and MDNY. All detections from this catalog were also manually reviewed. The full description of the data processing and creation of the catalog is provided in the article “Stress changes can trigger earthquake sequences in a hydrothermal region south of Istanbul” by Martínez-Garzón et al., currently under review in Geophysical Research Letters.

Description: The Earth system is accumulating energy due to human-induced activities. More than 90% of this energy has been stored in the ocean as heat since 1970, with similar to 60% of that in the upper 700 m. Differences in upper-ocean heat content anomaly (OHCA) estimates, however, exist. Here, we use a dataset protocol for 1970-2008-with six instrumental bias adjustments applied to expendable bathythermograph (XBT) data, and mapped by six research groups-to evaluate the spatiotemporal spread in upper OHCA estimates arising from two choices: 1) those arising from instrumental bias adjustments and 2) those arising from mathematical (i.e., mapping) techniques to interpolate and extrapolate data in space and time. We also examined the effect of a common ocean mask, which reveals that exclusion of shallow seas can reduce global OHCA estimates up to 13%. Spread due to mapping method is largest in the Indian Ocean and in the eddy-rich and frontal regions of all basins. Spread due to XBT bias adjustment is largest in the Pacific Ocean within 30 degrees N-30 degrees S. In both mapping and XBT cases, spread is higher for 1990-2004. Statistically different trends among mapping methods are found not only in the poorly observed Southern Ocean but also in the well-observed northwest Atlantic. Our results cannot determine the best mapping or bias adjustment schemes, but they identify where important sensitivities exist, and thus where further understanding will help to refine OHCA estimates. These results highlight the need for further coordinated OHCA studies to evaluate the performance of existing mapping methods along with comprehensive assessment of uncertainty estimates.

Description: The Earth climate system is out of energy balance, and heat has accumulated continuously over the past decades, warming the ocean, the land, the cryosphere, and the atmosphere. According to the Sixth Assessment Report by Working Group I of the Intergovernmental Panel on Climate Change, this planetary warming over multiple decades is human-driven and results in unprecedented and committed changes to the Earth system, with adverse impacts for ecosystems and human systems. The Earth heat inventory provides a measure of the Earth energy imbalance (EEI) and allows for quantifying how much heat has accumulated in the Earth system, as well as where the heat is stored. Here we show that the Earth system has continued to accumulate heat, with 381±61 ZJ accumulated from 1971 to 2020. This is equivalent to a heating rate (i.e., the EEI) of 0.48±0.1 W m−2. The majority, about 89 %, of this heat is stored in the ocean, followed by about 6 % on land, 1 % in the atmosphere, and about 4 % available for melting the cryosphere. Over the most recent period (2006–2020), the EEI amounts to 0.76±0.2 W m−2. The Earth energy imbalance is the most fundamental global climate indicator that the scientific community and the public can use as the measure of how well the world is doing in the task of bringing anthropogenic climate change under control. Moreover, this indicator is highly complementary to other established ones like global mean surface temperature as it represents a robust measure of the rate of climate change and its future commitment. We call for an implementation of the Earth energy imbalance into the Paris Agreement's Global Stocktake based on best available science. The Earth heat inventory in this study, updated from von Schuckmann et al. (2020), is underpinned by worldwide multidisciplinary collaboration and demonstrates the critical importance of concerted international efforts for climate change monitoring and community-based recommendations and we also call for urgently needed actions for enabling continuity, archiving, rescuing, and calibrating efforts to assure improved and long-term monitoring capacity of the global climate observing system. The data for the Earth heat inventory are publicly available, and more details are provided in Table 4.

Description: State of the climate in 2019

Description: Abstract

Description: The dataset contains three seismicity catalogs covering the first 5 days of the aftershock sequence of the Mw 7.8 Karamanmaraş and Mw 7.6 Elbistan earthquakes that occurred in Türkiye on February 6th, 2023. The catalogs are derived from machine learning (ML) approaches operating on continuous data from 38 permanent seismological stations covering the area of the aftershock sequence and span the time interval 06.02.2023-10.02.2023. The seismological stations are operated by AFAD (Disaster and Emergency Management Presidency of Turkey) and KOERI (Kandilli Observatory and Earthquake Research Institute). Automatic P- and S-phase picks were obtained using the deep learning PhaseNet software (Zhu & Beroza, 2019), and either GaMMA (Zhu et al., 2022) or GENIE (McBrearty & Beroza, 2023) routines were used to associate these phases into seismic events. The probabilitic NLLoc earthquake location software (Lomax et al., 2009) was used to produce single event locations and final relative relocations were obtained after applying the hypoDD software (Waldhauser & Ellsworth, 2000). This resulted in two single event location NLLoc aftershock catalogs based on GaMMA and GENIE event association and containing 17,550 and 14,805 event detections in the time interval 06.02.2023 01:18 UTC - 11.02.2023 00:00 UTC, respectively. The hypoDD based catalog of better constrained relative relocations contains 5,215 events. The magnitude range is between M-0.1 and M6.9 with time-variable magnitude of completeness. The catalog covers the area 36.00S-39.00S and 35.40E-40.00E. The full description of the data and methods is provided in the data description file.