0
Article Tier 2 Environmental Sources Marine & Wildlife Sign in to save

Water striders are impervious to raindrop collision forces and submerged by collapsing craters

Proceedings of the National Academy of Sciences 2024 11 citations

AI summary Read the abstract

Researchers used high-speed videography to study how water striders survive raindrop impacts, even though raindrops can weigh over 40 times their body mass. They found that the insects are briefly submerged but are ejected back to the surface by rebounding water jets, aided by their low density and water-repellent properties. The study identified a critical acceleration threshold that determines whether water striders are safely ejected or trapped underwater after a second crater collapse.

Water striders are abundant in areas with high humidity and rainfall. Raindrops can weigh more than 40 times the adult water strider and some pelagic species spend their entire lives at sea, never contacting ground. Until now, researchers have not systematically investigated the survival of water striders when impacted by raindrops. In this experimental study, we use high-speed videography to film drop impacts on water striders. Drops force the insects subsurface upon direct contact. As the ensuing crater rebounds upward, the water strider is propelled airborne by a Worthington jet, herein called the first jet. We show the water strider's locomotive responses, low density, resistance to wetting when briefly submerged, and ability to regain a super-surface rest state, rendering it impervious to the initial impact. When pulled subsurface during a second crater formation caused by the collapsing first jet, water striders face the possibility of ejection above the surface or submersion below the surface, a fate determined by their position in the second crater. We identify a critical crater collapse acceleration threshold ∼ 5.7 gravities for the collapsing second crater which determines the ejection and submersion of passive water striders. Entrapment by submersion makes the water strider poised to penetrate the air-water interface from below, which appears impossible without the aid of a plastron and proper locomotive techniques. Our study is likely the first to consider second crater dynamics and our results translate to the submersion dynamics of other passively floating particles such as millimetric microplastics atop the world's oceans.

More Papers Like This

Article Tier 2

Droplet impact on a particle-laden liquid interface: Worthington jet dynamics and microplastic ejection from floating rafts.

AI summary Read the abstract

Scientists studied what happens when raindrops hit water surfaces covered with tiny particles, using particles of different sizes and water-repellent properties. They found that how well particles stick to the water surface determines whether raindrops cause splashing, particle ejection, or create jets that can launch microplastics into the air.

Article Tier 2

Tiny water-walking bugs provide scientists with insights on how microplastics are pushed underwater

AI summary Read the abstract

Researchers studied water-walking insects to understand the surface tension and hydrodynamic forces that determine whether microplastic particles float or sink, providing mechanistic insight into how plastic pollutants move at the water surface interface. Understanding the physical mechanisms governing microplastic transport in water bodies is essential for modeling contamination spread and predicting exposure risk for aquatic organisms across different depth zones.

Article Tier 2

The key role of surface tension in the transport and quantification of plastic pollution in rivers

AI summary Read the abstract

Researchers discovered that surface tension — the same force that lets insects walk on water — traps a large portion of floating plastic in rivers at the water's surface, meaning current monitoring methods that only sample the surface may underestimate total riverine plastic pollution by up to 90%.

Article

Droplet Impact on Microparticle Raft: Wettability, density and size govern splashing and microplastic ejection from rafts under raindrop impact

AI summary Read the abstract

Raindrop impact on floating microplastic rafts drives particle ejection into the atmosphere, with particle wettability being the key determinant — superhydrophobic particles form armored Worthington jets that fragment into airborne liquid marbles carrying microplastics. This mechanism quantifies how rainfall over ocean surfaces can aerosolize microplastics, contributing to their global atmospheric transport and deposition on land.

Article

Droplet Impact on Microparticle Raft: Wettability, density and size govern splashing and microplastic ejection from rafts under raindrop impact

AI summary Read the abstract

Laboratory experiments revealed that raindrop impact on floating microplastic rafts drives particle ejection into the atmosphere, with particle wettability being the key determinant — superhydrophobic particles form armored Worthington jets that fragment into airborne liquid marbles carrying microplastics. This mechanism quantifies how rainfall over ocean surfaces can aerosolize microplastics, contributing to their global atmospheric transport and deposition on land.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper