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Scientists comment on a 7.5 magnitude earthquake in Venezuela.
Dr Raffaele De Risi, Associate Professor in Civil Engineering, University of Bristol, said:
“First, our thoughts are with the families. This is an unfolding human tragedy, and everything below should be read in that light. One framing point up front: what we are seeing so far broadly aligns with what the USGS PAGER system led us to expect for an event of this size, depth, and location. The data are consistent with the forecast; this is a catastrophe on the ground, but it is not a scientific surprise.”
What do we know so far about the geology/science?
“The sequence sits on the broad transform boundary between the Caribbean and South American plates, expressed in northern Venezuela through the Boconó–Morón–El Pilar fault system, a complex series of right-lateral strike-slip faults that run roughly 1,300 km across northern Venezuela. These were shallow crustal events: the first was an Mww 7.2 east-northeast of San Felipe at about 22 km depth, and 39 seconds later an Mww 7.5 struck just to the north, southeast of Yumare, at about 10 km depth. The USGS moment-tensor solutions indicate strike-slip faulting (for the foreshock, either left-lateral slip on an east-west fault or right-lateral slip on a north-south fault), exactly the mechanism expected on this margin. Strong shaking was felt in Guaria (where most of the damage is localised) and Caracas, roughly 170 km to the east. Tsunami advisories were issued for parts of the Caribbean but forecast wave heights remained small (below about a foot for Puerto Rico and the US Virgin Islands), and no significant marine impact was expected, consistent with the largely horizontal motion of a strike-slip rupture.”
Why two large earthquakes so close together — a “doublet”?
“A doublet differs from an ordinary mainshock–aftershock sequence. In a typical sequence, a large quake is followed by much smaller aftershocks; doublets are earthquakes of similar magnitude that are causally linked but seismologically distinct, i.e. the energy arrives in two separate packets from, usually, different sources. Here, the epicentres were only kilometres apart, but the USGS waveform data suggest they likely originated from different faults with different rupture styles, consistent with maps showing large strike-slip faults linked with arrays of smaller faults in various orientations. The most likely explanation is that the first rupture triggered the second: static stress transfer onto the adjacent fault, combined with passing dynamic waves, pushed an already-loaded segment past its failure threshold. A 39-second gap is well within the expected triggering window. It is uncommon but not unprecedented; the 2023 Kahramanmaraş M7.8/M7.5 sequence is a recent comparison.”
Liquefaction and landslides?
“The USGS ground-failure products tell a consistent story. The region is mountainous, so the landslide model anticipates widespread slope failures and ground failure, including landslides and liquefaction, throughout the region. Liquefaction is expected in the saturated, loose sediments of the coastal plains and river valleys. A specific aggravating factor for the capital is site response: the sediments beneath Caracas amplify seismic waves and enhance earthquake damage, so even at this distance, the basin can concentrate and prolong shaking. These remain modelled estimates; the true extent will only be confirmed through field reconnaissance and satellite imagery over the coming days.”
Was this earthquake possible to predict?
“No — and this needs to be said plainly. Predicting a specific earthquake’s time, location, and magnitude in advance is currently impossible; no scientific method exists to do so, and claims to the contrary should be treated with great scepticism. What science can do is two different things: long-term probabilistic hazard assessment (we know this fault system is active and capable of large strike-slip earthquakes, which is why it is mapped as a major hazard), and rapid post-event impact estimation. The USGS PAGER system did the latter within minutes, issuing a red alert with the corresponding fatality and economic-loss estimates. That is forecasting consequences after the event, not predicting the event itself — a distinction that matters, because conflating the two fuels false expectations.”
What is the response, and is it adequate? What about the buildings?
“Here, I would be careful about the limits of what we can say with certainty, while giving the structural context that explains the concern.
“On performance, it is too early for any meaningful engineering judgement. Reports of collapses are arriving, and the number of casualties and injuries is rising by the hour but understanding how and why the building stock behaved requires systematic damage surveys that have not yet been carried out. What we can describe is the exposure (i.e. the kinds of buildings in the shaken region and their known vulnerabilities), which is what rapid screening and triage will need to prioritise.
“The dominant typology across the affected zone is reinforced-concrete moment frames with masonry infill. The recurring weaknesses in this stock are familiar and dangerous in strong shaking — open or weak ground floors used for parking and commerce (soft storeys), short columns, plan torsion, poor beam-column joints in older buildings, irregular infill, and pounding between adjacent structures. The age of the building matters enormously: stock built before the major code reforms of 1967 and especially 1982 is the priority, with inadequate confinement, weak joints and limited transverse reinforcement. Along the coast, the marine environment promotes deterioration and reinforcement corrosion, further reducing capacity.
“Two other groups deserve specific mention. 1 non-engineered, incrementally built RC/masonry constructions, often extended vertically without analysis, on low-strength concrete, sometimes founded on fill or steep slopes, where seismic damage can combine directly with slope movement and retaining-wall failure, tying back to the ground-failure concern above. 2 Closer to the source, the stock is more likely to be low-rise masonry, owner-built frames, and some unreinforced brick or adobe, where out-of-plane wall failure and poor wall-to-roof connections are the main risks. Ports, the airport and petrochemical facilities bring a different set of concerns — connection and brace damage, drift, and damage to tanks and pipelines. So far, most damage is observed in mid-rise buildings.
“On codes: the current national standard, COVENIN 1756-1:2019, is a modern seismic-design framework — it replaced the 2001 edition, covers site classification, near-fault effects, liquefaction and slopes, and includes provisions (Chapter 12) for evaluating and strengthening existing buildings. So, the regulatory framework itself is sound and up to date. The decisive question, which only post-event assessment can answer, is how much of the standing stock predates these provisions or was built informally outside them.
“On the emergency response, it is not possible to comment with certainty while the situation is still unfolding. What can be said is that the scale of impact is consistent with the USGS PAGER red alert, meaning a response commensurate with a major disaster — large-scale search and rescue, medical surge and likely international assistance — is what the situation demands. One technical point worth flagging for the recovery phase: emergency occupancy decisions must rest on authorised rapid-safety assessments, not on appearances. Visible masonry-infill damage alone does not establish whether an RC building is safe, and conversely, apparently minor infill cracking can conceal serious column or joint distress. Any verdict on whether the overall response was adequate will have to wait until the picture stabilises.
“Our solidarity is with the people of Venezuela, the families who have lost loved ones, and the rescue teams working in extremely difficult conditions. We hope that international humanitarian assistance reaches the affected regions quickly.”
Prof Anastasios Sextos, Professor of Earthquake Engineering, University of Bristol, said:
What do we know so far about the geology/science behind the earthquake?
“Northern Venezuela sits on the boundary between the Caribbean Plate and the South American Plate. The main fault structure involved is the Boconó-Morón-El Pilar Fault System. This is a right-lateral strike-slip fault over 1,300 km long, comparable in character to California’s San Andreas Fault. The Yaracuy region near the epicentres is tectonically active; historical records include the 1812 earthquake that destroyed Caracas and the 1900 M7.7 event. The region has long been identified as a major seismic hazard zone; hence, this earthquake is not unprecedented.”
What causes two large earthquakes so soon after each other, a ‘doublet’?
“This is a similar mechanism to the 2023 Kahranmanmaras earthquake in Turkey. The general rule is that a strong earthquake is followed by aftershocks that are about one magnitude lower compared to the mainshock (e.g., a magnitude M6.5 quake may be followed by a 5.3-5.5M aftershock). However, when the main event is very strong, as it is in this case (i.e., beyond M7.0), there is strong possibility that the stress field is altered in nearby faults or across the same fault, thus triggering a second main shock. This is particularly detrimental given that the structures are exposed to two very strong main shocks back-to-back.”
What do we know about other impacts such as liquefaction and landslides?
“Yes. Both have been observed. USGS PAGER estimates liquefaction exposure of 10,000–100,000 people and landslide exposure of 1,000–10,000 people. River valleys, coastal plains, and reclaimed land (common along La Guaira and the Caracas valley floor) are at high liquefaction risk because sandy soils are susceptible to liquefaction.”
Was this earthquake possible to predict?
“Earthquake cannot be predicted short term as per current knowledge. However, after a very strong event above magnitude Mw7.0, a second equally strong or stronger earthquake was probable.”
What response is being taken, and is it adequate?
“This is difficult to assess given the current political landscape in Venezuela. The government declared a state of emergency and a tsunami warning was automatically issued. Several countries worldwide have expressed their willingness to help in search and rescue operations. This is critical for the next 48 hours.”
Dr Matthew Blackett, Associate Professor in Natural Hazards, Coventry University, said:
What do we know so far about the geology/science behind the earthquake?
“Northern Venezuela sits between the Caribbean Plate and the South American Plate, and these slide past each other (strike slip fault). This means quakes here are often shallow, such as these (around 10–20 km deep), which gives no time for dissipation of energy, so it arrives quickly at the surface and causes maximum damage. This is the largest (set of) quakes for 200 years, so much tension will have been built up over time – and that was released with these events.”
What causes two large earthquakes so soon after each other, a ‘doublet’?
“A doublet is when one large earthquake transfers stress onto a neighbouring section of fault, triggering another rupture/earthquake; in this case it was just 39 seconds and a few kms. This is uncommon. Because shaking is repeated, doublets often cause more damage i.e. the first weakens buildings, the second destroys them; people are also still in shock and disoriented before the next arrives. “
What do we know about other impacts such as liquefaction and landslides?
“These are important secondary hazards. Probably too early to assess their full extent. Liquefaction is possible wherever unconsolidated, water-saturated sediments are shaken, causing particles to lose friction amongst themselves and create a liquid. This will have happened at the coast and in estuarine areas. Landslides are a concern because steep slopes surround much of the affected region (caused in part by tectonic activity). These will block roads and access, hampering relief efforts. They could also destroy anything on them or beneath them. We’ll also get many aftershocks, causing more of the above and further hindering rescue efforts.”
Was this earthquake possible to predict?
“No. There is currently no reliable way to predict the exact time, location and magnitude of an earthquake. Scientists know where earthquakes are likely but cannot say that a major earthquake will occur on a particular day or precise point. Earthquake early warning systems exist, but these provide only seconds of notice after a quake has begun. This is very different from prediction, and no such system is in place in Venezuela.”
What response is being taken, and is it adequate?
“The immediate priority is the “golden 72 hours”, when search-and-rescue teams have the best chance of finding survivors trapped beneath collapsed buildings. The problem is that after decades of economic crisis, the buildings there are likely to have been poorly maintained, informal buildings will be common (meeting no seismic regulations) and the emergency services will be under-funded. If the airport remains closed, getting in external assistance will be problematic.”
Dr. Laura C Gregory, Associate Professor in Earthquake Geology, University of Leeds, said:
What do we know so far about the geology/science behind the earthquake?
“The magnitude 7.2 and 7.5 earthquakes struck northern Venezuela in the evening of the 24th June. These earthquakes ruptured along a strike-slip fault, that is, one where the crust on either side of the fault line slides horizontally. If you are standing on one side of this particular fault, the ground on the other side would move towards your right, in a ‘right-lateral strike-slip’ motion.
“The geology in this region is a complex pattern of faults that are accommodating the motion between the Caribbean and South American tectonic plates, with a few other smaller plates in the mix. These plates slide past one another at about 2 centimetres per year, which is fairly quick, geologically speaking. Given the rate of motion and how it is distributed across the major faults in the area, we might expect a M7 earthquake every 100 – 200 years (or so).
“The fault line is oriented east-west, and initial interpretations look like the earthquake originated about 170 km to the west of the Caracas. However, earthquakes are not just a dot on the map, but they extend along fault lines by 10’s to 100’s of kilometres. Based on the locations of the aftershocks, the M 7.5 earthquake might have travelled east, towards Caracas. Imagine the earthquake starting at a point at on the fault and expanding out towards Caracas. This ‘directivity’ can sometimes make the shaking worse, though we do not yet know the exact details for this event. The length of an earthquake scales with its size, and a M 7.5 earthquake may be expected to cover an area about 150 – 200 km long.”
What causes two large earthquakes so soon after each other, a ‘doublet’?
“Though rare, two large earthquakes occurring soon after one another has been observed and was even proposed to have happened in this region in 1812. Yesterday’s 7.5 earthquake or started 33 seconds after the 7.2. The term ‘doublet’ implies that the two earthquakes are distinct enough to be separated out, though they are most certainly related. Earthquakes are affected by complexities on the faults – often a large earthquake is a series of smaller events that break distinct patches of a fault separated by structural barriers. It is currently unclear exactly how the two earthquakes are related, but we will be able to distinguish how they evolved in time in space as more data become available.”
What do we know about other impacts such as liquefaction and landslides?
“Norther Venezuela has mountainous terrain and unstable slopes, as well as land that may be susceptible to liquefaction. The USGS has released maps where landslides and liquefaction are likely to occur, which suggest the population exposed is significant (over 1,000) to extensive (over 100,000), respectively. The complex nature of shaking resulting from two earthquakes occurring so close in space and time might amplify related effects, like liquefaction.”
Was this earthquake possible to predict?
“We simply cannot predict any earthquake. It is currently impossible to know exactly when and where any large earthquakes may occur, and it is unscientific to suggest otherwise. However, we can use careful geological and geophysical investigations to determine where it is likely for large earthquakes to occur. We can estimate how large earthquakes can be and approximately where they might occur. We use measurements of how fast the earth’s surface is moving (due to plate tectonics), and this allows us to quantify how much ‘energy’ (elastic strain) is building up around faults. We can determine where faults are located by studying their effect on the earth’s surface – many earthquakes over thousands and millions of years affects the shape of the landscape in ways that geologists are skilled at interpreting to map the fault lines.
“For this area, there was a study published in 2017 that measured approximately how large an earthquake could be expected on the faults in this area, and they suggested that enough energy has built up that would correspond to a M 7 – 7.6 earthquake (Pousse-Beltran et al., 2017). There was a destructive pair of earthquakes in 1812 in the same region and of similar magnitude (7.1 and 7.4). These events in 1812 also occurred close in time, suggesting that this rather atypical ‘doublet’ behaviour is typical for this fault system.”
What response is being taken, and is it adequate?
“The response to earthquakes this large will be incredibly challenging. I cannot comment on what is in action, but the authorities and community response will be hampered by the damage or destruction of major infrastructure like roads and bridges, lack of power and water. The severity of shaking in the epicentral area is projected to have reached an intensity 9 (out of a scale of 10), which is violent and associated with heavy damage such as partial collapse of even substantial buildings and buildings shifted off of foundations. The media focus is largely on Caracas, which, despite being located nearly 200 km from the epicentre has sustained significant damage and collapse of major buildings. However, the damage in the epicentral region (e.g. Moron) might be far more severe. We have not heard much news from towns and villages in the epicentral region, which is never a good sign, as the destruction may have cut off communications.”
Dr Roberto Gentile, Assistant Professor in Catastrophe Risk Modelling, University College London (UCL), said:
“These two earthquakes are the largest instrumentally recorded in this part of Venezuela (1). The US Geological Survey (USGS) issued its highest-level “red alert” for both the magnitude 7.2 and magnitude 7.5 earthquakes, meaning widespread severe damage is expected and casualties could number in the thousands (2). The length of fault that ruptured is estimated at around 90 km, though it could be anywhere between roughly 50 and 150 km. We will not know precisely until scientist’s map where aftershocks are occurring. The two earthquakes struck just 39 seconds apart. This is consistent with the first rupture travelling along the fault and triggering a second break on a neighbouring section (3). USGS models estimate thousands of people were exposed to ground failure, including liquefaction and landslides (4 – Note: these USGS estimates have not yet been manually reviewed by a USGS scientist at the time of writing.)
The risk of casualties is likely increased by the type of buildings in the area. Around 85% of homes have walls made of brick or concrete block, according to a 2019 household survey projecting Venezuela’s 2011 census. Much of this construction is unreinforced, meaning it is particularly vulnerable to earthquake shaking (5).”
1 – https://earthquakeinsights.substack.com/p/catastrophic-m75-earthquake-strikes
2 – https://earthquake.usgs.gov/earthquakes/eventpage/us6000t7zc/pager
3 – https://www.earthquaketracker.org/earthquakes/event/us6000t7zp
4 – https://earthquake.usgs.gov/earthquakes/eventpage/us6000t7zc/ground-failure/summary
Professor Domniki Asimaki, Chair in Geotechnical Earthquake Engineering, Imperial College London, said:
“Landslides are likely to have been an issue in the epicentral area to the west of Caracas. Videos of landslides are emerging in the news, but I have no details at this point. Similarly with the vulnerable structures, landslides that were not triggered during the first event, may have come much closer to failure and catastrophically triggered by the M7.5 main shock. The USGS Pager analysis is the best that we have, noting that it is only a first order estimation. This is the current Pager Landslide map for the larger (M=7.5) of the two earthquakes: The USGS analysis is that the estimated population exposure for landslides is in the range of 1,000 to 10,000 and for liquefaction it is in the top of the range of 10,000-100,000 people.”
Dr Christian Malaga Chuquitaype, Reader in Structural Dynamics and Seismic Engineering at Imperial College London, said:
“The images coming out of Venezuela are hard to watch. Buildings pancaked. Entire blocks flattened. Widespread damage. Unfortunately, the engineering explanation is not surprising to those of us who work in this field.
“Most of what collapsed appears to be what we call non-ductile concrete buildings; that is, buildings where structural elements like columns and beams simply don’t have enough steel, or the steel they have is not properly distributed, to absorb seismic energy without shattering. They tend to explode when they fail. And they are among the building types most likely to kill people during earthquakes. We keep seeing these images: Mexico, Turkey, the Philippines, and now Venezuela is, tragically, the latest entry in a long and familiar list.
“One thing that makes this event even more destructive is its double tap: a M7.2 followed 39 seconds later by a M7.5 (current USGS figures). A structure weakened by the first hit would have had no time to recover before the second blow. The casualty numbers are likely to rise in the hours ahead, and the structural, social, economic, environmental implications will last for months and years.
“The proximity of these events to densely populated areas make the situation all the more concerning. And the parallel with other Latin American cities is also deeply concerning. Cities like Lima in Peru, or those in Ecuador and Colombia. It is frustrating to see so many non-ductile concrete buildings still standing un-retrofitted across the region. The science and the tools have been available for decades. What we are witnessing in Venezuela is not a warning about something unknown. It is a reminder about something we already know and have the means to address. What we lack is money, policy, and urgency.
“My thoughts are with the victims of this terrible event.”
Ziggy Lubkowski, Associate Director and Arup’s seismic expert, said:
What do we know so far about the geology/science behind the earthquake?
“This earthquake occurred along the boundary between the Caribbean and South American tectonic plates, which run past Venezuela’s northern coast. These plates are moving relative to each other, building up strain that is periodically released as earthquakes.
“Early indications suggest this was a large, shallow strike‑slip event – meaning the plates moved horizontally past each other. Shallow earthquakes typically produce stronger shaking at the surface.
“Initial assessments indicate very strong shaking in parts of northern Venezuela, at levels capable of causing significant structural damage. While the scientific analysis is still evolving, the scale of shaking and the proximity to urban areas mean the impacts are likely to be severe.”
What causes two large earthquakes so soon after each other – a ‘doublet’?
“In some cases, what appears to be two separate earthquakes can actually be part of a single, complex rupture process. A large rupture doesn’t always propagate smoothly along a fault – it can occur in stages or pulses.
“In this case, two large releases of energy occurred within seconds. For people on the ground, that would likely have felt like one prolonged period of intense shaking, and this matches initial reports.
“This is important because prolonged or repeated shaking can significantly increase damage. Structures that are weakened by an initial shaking may be less able to withstand repeated shaking. While this kind of “doublet” behaviour is rare, it is a recognised feature of large earthquake events.”
What do we know about other impacts such as liquefaction and landslides?
“Earthquakes don’t just cause damage through shaking alone. They can also trigger a range of secondary hazards, which often contribute significantly to overall impact.
“Where there are loose, water‑saturated soils – common in coastal and low‑lying areas – ground shaking can cause liquefaction, where the soil temporarily behaves like a liquid. This can lead to buildings tilting or collapsing and infrastructure such as roads and pipelines failing.
“Similarly, strong shaking can trigger landslides, particularly in hilly or unstable terrain. These can damage buildings, block transport routes, and complicate rescue efforts.
“At this stage, it is likely that both liquefaction and landsliding have occurred in affected regions, but the full extent will only become clear as ground assessments are carried out. In practice, this is why seismic design considers not just the structure but the ground it sits on – something Arup routinely account for in projects in earthquake‑prone regions.”
Was this earthquake possible to predict?
“No – earthquakes cannot currently be predicted in terms of their exact timing, location and magnitude.
“What we can do is understand where earthquakes are likely to occur, based on tectonic setting, and design our infrastructure accordingly. This is a key part of earthquake engineering: accepting that these events will happen and ensuring that buildings and systems are resilient when they do.
“Global experience shows that the impact of earthquakes is not determined by magnitude alone, but by how well prepared the built environment is to withstand the shaking. Across the industry, including Arup’s own work on major infrastructure and buildings in seismic regions, the focus is on designing for these known risks – ensuring structures can withstand shaking and continue to function where it matters most.”
What response is being taken, and is it adequate?
“In the immediate aftermath of a major earthquake, the priority is search and rescue, medical response, and ensuring safety from further hazards such as aftershocks or unstable structures.
“At this stage, it is too early to assess the adequacy of the response. In many earthquake scenarios, it can take days or weeks to fully understand the scale of the damage and the resources required.
“What is clear is that response efforts are always more challenging where infrastructure has been heavily affected – particularly transport, communications, and utilities. This is why resilience is so important: not just to prevent collapse, but to enable rapid and effective response and recovery.”
What should people expect next?
“Aftershocks are expected following an earthquake of this size and can continue for weeks or months. The first aftershocks have already been reported. Although they are typically smaller, they can still cause further damage, particularly to buildings that have already been weakened.
“Damage assessments will take time. Early models provide a broad indication of potential impacts, but the full picture – both in terms of humanitarian consequences and economic losses – will only emerge over the coming weeks. This is why modern seismic engineering increasingly focuses on keeping critical infrastructure operational – an approach reflected in projects globally where hospitals, transport and utilities are designed to remain functional after major events.
Any other important scientific context?
“One of the key lessons from earthquakes globally is that hazard does not equal disaster. The same magnitude event can have very different outcomes depending on factors such as building standards, ground conditions, and population exposure.
“Earthquake engineering has made significant progress over recent decades, particularly in improving how buildings perform under shaking. However, events like this demonstrate that risk remains, especially where there is a combination of strong shaking, vulnerable structures, and dense urban populations.
“Ultimately, the focus is not just on preventing damage entirely – which may not be possible – but on reducing loss of life and ensuring that critical infrastructure continues to function during and after the event.”
Dr Stephen Hicks, Research Fellow and Lecturer in Environmental Seismology, University College London (UCL), said:
“Today’s magnitude 7.5 earthquake offshore Venezuela was preceded approximately 37 seconds earlier by a magnitude 7.2 foreshock, forming an unusual and complex earthquake sequence.
“Earthquakes of similar size that occur close together in both space and time are known as “earthquake doublets”. They have been documented in many parts of the world, but remain relatively uncommon.
“Research over the past few decades has shown that large earthquakes are often more complex than a single fault suddenly breaking. Instead, rupture can cascade across multiple fault segments or patches of a fault, with one rupture triggering another in rapid succession. Earthquake doublets represent one particularly clear example of this broader process, in which stress changes caused by one rupture can help trigger another nearby earthquake.
“Preliminary analyses suggest that today’s rupture propagated eastwards from its point of initiation towards Caracas. This is similar to the rupture direction inferred for the destructive 1967 Caracas earthquake.
“The direction in which a fault ruptures can have an important influence on the distribution of shaking. When an earthquake rupture propagates towards a populated area, seismic energy can become concentrated in that direction, producing stronger ground motions than would otherwise occur. This was the case of Caracas, which was in the “crosshairs” of the eastward earthquake rupture, and shaking may also have been amplified by the deep sedimentary deposits that underlie parts of the Caracas Valley.
“Taken together, these factors suggest that Caracas may have experienced particularly intense shaking during this event. While it is still too early to fully assess the consequences, the earthquake certainly had the potential to have caused significant damage, and detailed impact assessments are now underway.
“My thoughts are with all those affected by this earthquake and the emergency responders working in the impacted areas.”
Prof Joanna Faure Walker, Professor of Earthquake Geology and Disaster Risk Reduction, University College London (UCL), said:
“The two earthquakes occurred on east-west orientated faults with “right lateral” movement, which means if you were to stand on one side of the fault looking at it, the other side moved to the right in the earthquake. In Venezuela, the Caribbean plate is moving eastwards relative to the South American plates which causes such strike slip earthquakes. This strike-slip style of motion is what is seen on the San Andreas Fault in the United States and North Anatolian Fault in Turkey.
“Why were there two earthquakes? When a fault moves in an earthquake on one fault, this changes the stress on surrounding faults or further along the fault that ruptures in the case of partial rupture. This means that if surrounding faults are already near to failure, the stress transfer from another earthquake can bring the next fault or section of fault to failure, causing another earthquake.
“Earthquakes are not possible to predict, but in Venezuela because we know there is a plate margin we do know such earthquakes are possible and forecasting models can give indications of the likelihood and possible magnitudes. “
Prof Ilan Kelman, Professor of Disasters and Health, Institute for Risk and Disaster Reduction (IRDR), University College London (UCL), said:
“Caracas is well-known to be in a seismic zone, with examples of previous major earthquakes in 1812 and 1967. The country’s recent decades of difficult politics have meant that governance, such as for building codes and disaster preparedness, have suffered, leading to this disaster. The priority now is rescuing trapped people, treating the injured, supporting the survivors, and hopefully rebuilding to avoid creating the next disaster.”
Prof Dan Faulkner, Lecturer in Rock Mechanics, University of Liverpool, said:
“These earthquakes occurred on faults that were known and have produced large earthquakes in the past (e.g., 1812 Caracas Earthquake, 1900 Venezuela Earthquake, both of which were estimated to have been a similar size to the current ones).
“The South American tectonic plate in the south is moving westwards against the Caribbean tectonic plate to the north at ~20 mm/year – almost the rate at which your fingernails grow. We would expect large earthquakes to occur in these areas where tectonic plates meet and move past each other. This is a transcurrent plate boundary where earthquakes will occur at relatively shallow depth, meaning the intensity of shaking felt at the surface will be greater.
“The closely spaced (~40 seconds apart) earthquakes could be considered an ‘earthquake doublet’ or, because the earlier earthquake was smaller, it can be viewed as a foreshock. The second earthquake at M7.5 released almost 3 times as much energy as first M7.2 earthquake. The first will certainly have contributed towards the second occurring.
“The first earthquake would have produced slip over a ~60 km length of the fault, which would have transferred stress onto an adjacent part of the fault then then ruptured ~180 km length of the fault, likely towards the east were shaking heavily affected the capital, Caracas.
“We know regionally where large events are likely to happen – typically close to tectonic plate boundaries – but the accurate timing and location are still impossible to predict.”
Dr Karen Lythgoe, NERC Independent Research Fellow, University of Edinburgh, said:
“The seismic data shows that the earthquake or earthquakes were very scientifically complex. Initial reports are of one Mw7.2 followed by a Mw7.5 within a minute (38 seconds to be precise). But it takes about 30 seconds for a Mw7.2 to rupture, so it is possible that this is a single bigger event (of about Mw7.6-7.7) instead of two smaller ones. The seismic waves are all overlapping each other, so it will take seismologists some time to disentangle this scientifically.
“Complex ruptures like this happen because of variations of stress within rocks at shallow depths. When stress is released on one area in an earthquake, this changes the stress in other areas, and where the stress increases, other earthquakes can be triggered.
“The earthquakes occurred on a vertical fault, and the ground to the north moved to the east compared to the ground on the south. The fault is the boundary between the Caribbean and South American plates.
“Either way (a single big complex event or two smaller ones), the shaking was very large since the earthquakes happened at shallow depths, probably rupturing to the surface and so we can expect a lot of damage. The USGS is predicting over 10,000 fatalities and this is within the norm for such a big event close to populated areas. Shaking reports are of “violent” shaking and with heavy damage. In Caracas shaking is listed as “very strong” with moderate/heavy damage. The earthquake started in the west and ruptured to the east, towards Caracas (but likely stopping just before it), so this explains why the shaking is so large in Caracas (the seismic waves all bundle up in the direction of the earthquake rupture).
“Earthquakes can’t be predicted since they are essentially random. But scientists do forecast earthquakes. The fault that the earthquakes occurred on was known about and mapped, so the region was certainly known to have a high seismic hazard. “
Professor Bruce D. Malamud, Director, Institute of Hazard, Risk and Resilience, Durham University, said:
“These earthquakes occurred in a region of known seismic hazard. Northern Venezuela lies within a complex plate-boundary zone between the Caribbean and South American plates, with major active fault systems capable of producing large earthquakes. So, although the timing of this event could not have been predicted, the occurrence of damaging earthquakes in this broad region is not unexpected from a geological perspective.
“The reports of two large earthquakes occurring very close together are scientifically important, but they should not be interpreted as evidence that the second earthquake was predictable. When a smaller earthquake is followed by a larger one in the same sequence, the first event may be described retrospectively as a foreshock. That label can only be applied after the larger event has happened. In other cases, two similar large earthquakes close in time and space may be described as an earthquake doublet. At this early stage, the precise interpretation will depend on revised locations, depths, magnitudes and fault-rupture analysis.
“Earthquakes cannot currently be predicted in the sense most people mean: specifying the time, place and magnitude of a future earthquake. What scientists can do is identify regions with elevated long-term earthquake hazard, and from this estimate probabilities, improve building codes, support preparedness, and rapidly assess likely impacts after an earthquake has occurred.
“Following these earthquakes, the main immediate risks are not only from the shaking itself, but from damaged buildings, aftershocks, landslides on steep slopes, possible liquefaction in susceptible water-saturated sediments, disruption to hospitals, roads and utilities, and the difficulty of search and rescue in unstable structures. The priority now is life safety: search and rescue, medical care, shelter, clear public communication, assessment of damaged buildings, and avoiding re-entry into unsafe structures.
“It is too early to make a confident judgment from outside the country on whether the response is adequate. That will depend on access to affected areas, the condition of critical infrastructure, the availability of trained search-and-rescue teams, medical capacity, and whether clear advice is reaching people at risk from aftershocks, unstable buildings, landslides and other secondary hazards.”
Dr Richard Luckett, Seismologist at the British Geological Survey, said:
“Although Venezuela gets a lot of earthquakes, events of this scale are less common. In the last 100 years there have only been seven earthquakes recorded over magnitude 6, including a 6.6 magnitude event which occurred in 1967 and led to fatalities in Caracas.
“An earthquake of magnitude 7.5 in a heavily populated area is always going to be devastating to some degree – we do not know enough to comment on buildings or infrastructure although the fact the earthquakes were recorded at shallow depths will have contributed to the severity of the damage. “
Prof Bill McGuire, Emeritus Professor of Geophysical & Climate Hazards, University College London (UCL), said:
“Northern Venezuela, including the capital Caracas, is no strangers to earthquakes, and there have been five Magnitude 7+ quakes in the region in the last 100 years. The last to cause fatalities and high levels of damage in Caracas was in 1967, but that quake was far smaller than yesterday’s double whammy. There is a saying amongst seismologists and earthquake engineers – ‘earthquakes don’t kill people – buildings kill people’, and this is the reality in virtually every major quake, especially in majority world countries. Once again, in Venezuela, it looks as if high-rise buildings and apartment blocks have not been constructed well enough to survive the shaking of a quake of this size, and many have ‘pancaked’ – floor after floor collapsing on top of one another, leaving no spaces between, and little chance of survival. It would be no surprise at all to see a final death toll well into the thousands.”
Professor Mark Allen, Professor in the Department of Earth Sciences at Durham University, said:
“The two earthquakes which struck Venezuela on 24/6/26 were unusual for being so close together in time at this scale: a Magnitude 7.2 event was followed only 39 seconds later by a Magnitude 7.5 event. But, it is likely that the first earthquake ruptured one fault segment and transferred stress on to another fault which failed in turn, causing the second earthquake. The events seem to have taken place on the tectonic plate boundary between South America and the Caribbean. The plates are moving past each other, laterally, in this region – similar to the San Andreas Fault in California. The epicentres appear to be ~100 miles west of Caracas; whatever the casualties, earthquakes nearer would have been more destructive. There is a risk of further earthquakes (aftershocks) in the Caracas region: the Venezuelan capital is in an earthquake-prone area, and local faults may have been loaded by the 24/6/26 events.”
Declared interests
Dr Raffaele De Risi: “no interests to declare”
Prof Anastasios Sextos: “no COIs to declare.”
Dr Matthew Blackett: “I confirm that I have no interests which might be regarded by journalists or others as giving rise to a potential conflict.”
Dr. Laura C Gregory: “I have no competing interests. I have received funding from UKRI (NERC) – UK Research and Innovation. My background is in earthquake geology. I’ve not worked specifically in Venezuela but I have worked on earthquakes around the world.”
Professor Domniki Asimaki: “I have no conflict of interest.“
Dr Christian Malaga Chuquitaype: “No conflicts of interest “
Ziggy Lubkowski: “Declaration of interests:
I am a committee member of SECED, the UK society of earthquakes and dynamics. I am also the UK national delegate to the IAEE international association of earthquake engineering
I am on the BSi 525/8 committee for Eurocode 8 which deals with seismic design of buildings and infrastructure
I am on PIANC working group 225 for the seismic design of ports”
Dr Stephen Hicks: “No interests to declare”
Joanna Faure Walker: “No conflicts of interest”
Prof Ilan Kelman: “No interests to declare.”
Prof Dan Faulkner: “I have no industry links relating to any of the opinions above.
I was Head of Department from 2018-2023, and President of the Tectonophysics section of the American Geophysical Union (2022-2024) the largest global grouping of Earth and space scientists, that supports 130,000 enthusiasts worldwide.”
Dr Karen Lythgoe: “No conflicts of interests.”
Professor Bruce D. Malamud: “I have no relevant conflicts of interest to declare.”
Dr Richard Luckett: “We receive funding from our Customer Group for the UK National Monitoring Network and have done projects for many different customers and research for various bodies over the years.”
Prof Bill McGuire: “no DOIs”
Professor Mark Allen: “no DOIs”
For all other experts, no reply to our request for DOIs was received.